Login In
2016 Volume 36 Issue 9
2016, 36(9): 1973-1984
doi: 10.6023/cjoc201605007
Abstract:
In recent years, an explosive growth of reactivities of hypervalent iodine reagents has witnessed and these reagents, featuring facile availability and easy handleness, offer multiple advantages over establised methods as an efficient multipurpose oxidants, whose reactivities are similar to derivatives of mercury, chromium, lead, thallium and other heavy metals, but without the toxicity and environmental problems of these heavy metal agents. Thus, hypervalent iodine reagents have received much more attention from the synthetic chemists. This account mainly summarizes our recent research progress in the area of hypervalent iodine chemistry, especially focusing on the excellent performances and unique applications brought about by the new hypervalent iodine reagents and new combinations of them both developed in our group:(1) first utilization of a recyclable iodine(Ⅲ) reagent iodosodilactone for the direct esterification, amidation and peptide synthesis and high efficient liquid-phase oligo-peptide synthesis mediated by a more powerful iodosodilactone-type reagent, 6-(3, 5-bis-(trifluoro-methyl)phenyl)-1H, 4H-2aλ3-ioda-2, 3-dioxacyclopenta[hi]indene-1, 4-dione (FPID); (2) design, synthesis and reactivity explo-ration of a new water-soluble hypervalent iodine(V) reagent, 5-trimethylammonio-1, 3-dioxo-1, 3-dihydro-1λ5-benzo[d]-[1, 2]iodoxol-1-ol anion (AIBX); (3) systematic studies of reactivities of the first hypervalent iodine(Ⅲ) reagent iodobenzene dichloride.
In recent years, an explosive growth of reactivities of hypervalent iodine reagents has witnessed and these reagents, featuring facile availability and easy handleness, offer multiple advantages over establised methods as an efficient multipurpose oxidants, whose reactivities are similar to derivatives of mercury, chromium, lead, thallium and other heavy metals, but without the toxicity and environmental problems of these heavy metal agents. Thus, hypervalent iodine reagents have received much more attention from the synthetic chemists. This account mainly summarizes our recent research progress in the area of hypervalent iodine chemistry, especially focusing on the excellent performances and unique applications brought about by the new hypervalent iodine reagents and new combinations of them both developed in our group:(1) first utilization of a recyclable iodine(Ⅲ) reagent iodosodilactone for the direct esterification, amidation and peptide synthesis and high efficient liquid-phase oligo-peptide synthesis mediated by a more powerful iodosodilactone-type reagent, 6-(3, 5-bis-(trifluoro-methyl)phenyl)-1H, 4H-2aλ3-ioda-2, 3-dioxacyclopenta[hi]indene-1, 4-dione (FPID); (2) design, synthesis and reactivity explo-ration of a new water-soluble hypervalent iodine(V) reagent, 5-trimethylammonio-1, 3-dioxo-1, 3-dihydro-1λ5-benzo[d]-[1, 2]iodoxol-1-ol anion (AIBX); (3) systematic studies of reactivities of the first hypervalent iodine(Ⅲ) reagent iodobenzene dichloride.
2016, 36(9): 1985-1993
doi: 10.6023/cjoc201604036
Abstract:
Guanidines are a unique class of tri-nitrogen compounds having various bioactivities, which are wildly presented in natural products and drug molecules, and they are wildly used in pharmacy and pesticide fields. Moreover, they have high application value in organic synthesis and functional materials. The synthesis of guanidines has received much attention due to their unique structures and widespread application value. Recently, lots of new synthetic methods of guanidines, especially the synthetic methods based on highly efficient transition metal-catalyzed reactions, have been developed. The recent progress in transition metal-catalyzed reactions developed for the synthesis of guanidines in the past twenty years is summarized. The synthetic methods for various guanidines are introduced comprehensively, and the characteristics and disadvantages of these methods are also discussed, thus it may be helpful for the research on transition metal-catalyzed synthesis of guanidines.
Guanidines are a unique class of tri-nitrogen compounds having various bioactivities, which are wildly presented in natural products and drug molecules, and they are wildly used in pharmacy and pesticide fields. Moreover, they have high application value in organic synthesis and functional materials. The synthesis of guanidines has received much attention due to their unique structures and widespread application value. Recently, lots of new synthetic methods of guanidines, especially the synthetic methods based on highly efficient transition metal-catalyzed reactions, have been developed. The recent progress in transition metal-catalyzed reactions developed for the synthesis of guanidines in the past twenty years is summarized. The synthetic methods for various guanidines are introduced comprehensively, and the characteristics and disadvantages of these methods are also discussed, thus it may be helpful for the research on transition metal-catalyzed synthesis of guanidines.
2016, 36(9): 1994-2010
doi: 10.6023/cjoc201604001
Abstract:
The recent progress in the cycloaddition reactions of nitroso compounds with various compounds is reviewed, including[2+2], [3+2], [2+2+1], [3+3], [4+1] and [4+2] cycloaddition reactions. Moreover, the prospects of future development are also discussed.
The recent progress in the cycloaddition reactions of nitroso compounds with various compounds is reviewed, including[2+2], [3+2], [2+2+1], [3+3], [4+1] and [4+2] cycloaddition reactions. Moreover, the prospects of future development are also discussed.
2016, 36(9): 2011-2023
doi: 10.6023/cjoc201605004
Abstract:
Organosilicon compounds have a wide range of applications in organic synthesis. It can be readily converted to a series of functional compounds through a simple operation. In the recent years, copper-catalyzed conjugate silylation of unsaturated compounds has emerged as a novel synthetic tool to introduce a variety of organosilicon compounds. Herein, this research progress, especially the development in the asymmetric conjugate silylation is summarized.
Organosilicon compounds have a wide range of applications in organic synthesis. It can be readily converted to a series of functional compounds through a simple operation. In the recent years, copper-catalyzed conjugate silylation of unsaturated compounds has emerged as a novel synthetic tool to introduce a variety of organosilicon compounds. Herein, this research progress, especially the development in the asymmetric conjugate silylation is summarized.
2016, 36(9): 2024-2038
doi: 10.6023/cjoc201603034
Abstract:
1, 3-Benzothiazinone derivatives have widely bioactivities. So the methods for the synthesis of these 1, 3-benzothiazinone derivatives have attracted enormous attentions worldwide. From the method of introducing sulfur atom and the reaction mechanism for the formation of benzothiazinone derivatives, the method of synthesizing 1, 3-benzothiazinone derivatives has been summarized in this review. So the thiophenol derivatives, disulfide derivatives, the same carbon connected with amino and mercapto derivatives, isothiocyanate derivatives and some smaller sulfur molecules are used as starting materials.
1, 3-Benzothiazinone derivatives have widely bioactivities. So the methods for the synthesis of these 1, 3-benzothiazinone derivatives have attracted enormous attentions worldwide. From the method of introducing sulfur atom and the reaction mechanism for the formation of benzothiazinone derivatives, the method of synthesizing 1, 3-benzothiazinone derivatives has been summarized in this review. So the thiophenol derivatives, disulfide derivatives, the same carbon connected with amino and mercapto derivatives, isothiocyanate derivatives and some smaller sulfur molecules are used as starting materials.
2016, 36(9): 2039-2052
doi: 10.6023/cjoc201603046
Abstract:
Secure and efficient gene carrier has important application in gene therapy. Compared with viral gene vectors, non-viral gene vec-tor has attracted much attention because of their low immunogenicity, easy mass production and low costs. However, they showed limited activity in transfection efficiency and selectivity. This paper reviewed recent research progress in dendritic poly-mers gene carriers, including (ⅰ) dendritic and derived materials, (ⅱ) supramolecular parent materials, such as the carrier combined with cyclodextrins, and cucurbituril in multivariate and block type pattern, (ⅲ) dendritic polymers gene vector combined with inorganic material, such as gold nanoparticles, iron oxide nanoparticles and graphene, and (ⅳ) functional response type dendritic polymers gene vector, such as the pH response type vector, two disulfide response type vector, redox hyperbranched gene carrier and fluorinated dendrimers as gene vectors.
Secure and efficient gene carrier has important application in gene therapy. Compared with viral gene vectors, non-viral gene vec-tor has attracted much attention because of their low immunogenicity, easy mass production and low costs. However, they showed limited activity in transfection efficiency and selectivity. This paper reviewed recent research progress in dendritic poly-mers gene carriers, including (ⅰ) dendritic and derived materials, (ⅱ) supramolecular parent materials, such as the carrier combined with cyclodextrins, and cucurbituril in multivariate and block type pattern, (ⅲ) dendritic polymers gene vector combined with inorganic material, such as gold nanoparticles, iron oxide nanoparticles and graphene, and (ⅳ) functional response type dendritic polymers gene vector, such as the pH response type vector, two disulfide response type vector, redox hyperbranched gene carrier and fluorinated dendrimers as gene vectors.
2016, 36(9): 2053-2074
doi: 10.6023/cjoc201604002
Abstract:
Highly selective and sensitive detection of nitro aromatic explosive picric acid (PA) has become a challenging task due to the increasing concerns over national security and environmental awareness. In order to adjust to the trend of green chemistry, more and more attention has been attached to the fluorescent probes among various PA detection techniques, especially the organic molecule fluorescent probes without any metal ion (e.g. Hg2+)-assisted fluorescence enhancement for their easy availability and good processability. According to the molecular composition of the probes, these organic molecule probes can be classified into three categories as polymer, oligomer, and small molecule type. The progress on their molecular design and synthesis is reviewed, and their future trend is also prospected.
Highly selective and sensitive detection of nitro aromatic explosive picric acid (PA) has become a challenging task due to the increasing concerns over national security and environmental awareness. In order to adjust to the trend of green chemistry, more and more attention has been attached to the fluorescent probes among various PA detection techniques, especially the organic molecule fluorescent probes without any metal ion (e.g. Hg2+)-assisted fluorescence enhancement for their easy availability and good processability. According to the molecular composition of the probes, these organic molecule probes can be classified into three categories as polymer, oligomer, and small molecule type. The progress on their molecular design and synthesis is reviewed, and their future trend is also prospected.
2016, 36(9): 2075-2090
doi: 10.6023/cjoc201604005
Abstract:
The recent progress in lanthanide metals catalyzed asymmetric cycloaddition reactions is reviewed, mainly including[4+2], [3+2], [2+2] and[2+1] asymmetric cycloaddition reactions. Moreover, the possible mechanisms of some parts of reactions are also discussed.
The recent progress in lanthanide metals catalyzed asymmetric cycloaddition reactions is reviewed, mainly including[4+2], [3+2], [2+2] and[2+1] asymmetric cycloaddition reactions. Moreover, the possible mechanisms of some parts of reactions are also discussed.
2016, 36(9): 2091-2104
doi: 10.6023/cjoc201604034
Abstract:
Platencin was isolated from a new strain of Streptomyces platensis MA7339 found in a soil sample collected in Spain. It has a novel molecular structure and exhibits a broad spectrum of antibacterial activity. In this review, the progresses since 2010 in the total synthesis of platencin are summarized with an emphasis on the synthetic strategies of the routes.
Platencin was isolated from a new strain of Streptomyces platensis MA7339 found in a soil sample collected in Spain. It has a novel molecular structure and exhibits a broad spectrum of antibacterial activity. In this review, the progresses since 2010 in the total synthesis of platencin are summarized with an emphasis on the synthetic strategies of the routes.
2016, 36(9): 2105-2120
doi: 10.6023/cjoc201602034
Abstract:
Linear α-olefin is an important feed stock for chemical industry. Production of specific α-olefin through selective ethylene oligomerization catalyzed by homogeneous chromium-based catalysts is an important research on orientation under rapid development in recent years. The research of catalytic mechanism plays an important role in guiding the exploration of novel high-efficient catalysts. The application of methods such as labelled atom, organometallic precursor, EPR-XAS, density functional theory (DFT) calculation etc. in the research of reaction path and the metal oxidation state is introduced, with the latest achievement in the mechanistic research summarized. Research works carried out by various researchers are compared and discussed from methodology. New perspective on binuclear Cr metal ring mechanistic research is proposed and an outlook on the further research orientation is presented.
Linear α-olefin is an important feed stock for chemical industry. Production of specific α-olefin through selective ethylene oligomerization catalyzed by homogeneous chromium-based catalysts is an important research on orientation under rapid development in recent years. The research of catalytic mechanism plays an important role in guiding the exploration of novel high-efficient catalysts. The application of methods such as labelled atom, organometallic precursor, EPR-XAS, density functional theory (DFT) calculation etc. in the research of reaction path and the metal oxidation state is introduced, with the latest achievement in the mechanistic research summarized. Research works carried out by various researchers are compared and discussed from methodology. New perspective on binuclear Cr metal ring mechanistic research is proposed and an outlook on the further research orientation is presented.
2016, 36(9): 2121-2129
doi: 10.6023/cjoc201603002
Abstract:
A novel visible-light-introduced reaction for the construction of oxindole derivatives via tandem radical cyclization of N-aryl acrylamides with diethyl bromomalonate has been developed. The reaction has been achieved in high yield under mild conditions by using Eosin Y as photocatalyst, which is cheap, easy to handle and environmentally friendly. It might provide a promising protocol for the synthesis of oxindole derivatives.
A novel visible-light-introduced reaction for the construction of oxindole derivatives via tandem radical cyclization of N-aryl acrylamides with diethyl bromomalonate has been developed. The reaction has been achieved in high yield under mild conditions by using Eosin Y as photocatalyst, which is cheap, easy to handle and environmentally friendly. It might provide a promising protocol for the synthesis of oxindole derivatives.
2016, 36(9): 2130-2135
doi: 10.6023/cjoc201604039
Abstract:
The method for the synthesis of bi-functionalized pillar[5]arenes with amino and ester groups or amino and carboxylic group has been developed. The conformation of the functional group of the pillar[5]arene was investigated by using 1H NMR and X-Ray experiments. The intramolecular hydrogen bonding induces the side-chain of the pillar[5]arene to introvert. And thus, the amino group points to the inside cavity of the pillar[5]arene backbone. The position of the amino group is adjustable by using alkyl chains with different length.
The method for the synthesis of bi-functionalized pillar[5]arenes with amino and ester groups or amino and carboxylic group has been developed. The conformation of the functional group of the pillar[5]arene was investigated by using 1H NMR and X-Ray experiments. The intramolecular hydrogen bonding induces the side-chain of the pillar[5]arene to introvert. And thus, the amino group points to the inside cavity of the pillar[5]arene backbone. The position of the amino group is adjustable by using alkyl chains with different length.
2016, 36(9): 2136-2141
doi: 10.6023/cjoc201603043
Abstract:
An efficient and practical palladium-catalyzed cascade oxidative heterocyclization has been developed to afford functionalized oxygen-containing five-membered heterocycles in moderate to good yields with high regio-and diastereo-selectivities. Their structures were confirmed by IR, 1H NMR, 13C NMR and HRMS. Furthermore, the current methodology could also be conveniently applied to the synthesis of naturally occurring biologically active functionalized tetrahydrofurans and γ-lactones frameworks.
An efficient and practical palladium-catalyzed cascade oxidative heterocyclization has been developed to afford functionalized oxygen-containing five-membered heterocycles in moderate to good yields with high regio-and diastereo-selectivities. Their structures were confirmed by IR, 1H NMR, 13C NMR and HRMS. Furthermore, the current methodology could also be conveniently applied to the synthesis of naturally occurring biologically active functionalized tetrahydrofurans and γ-lactones frameworks.
2016, 36(9): 2142-2149
doi: 10.6023/cjoc201603045
Abstract:
To explore the chemical space of protein tyrosine phosphatase 1B (PTP1B) inhibitors by changing bis-aromatic amide moiety into aromatic amide moiety, a series of aromatic amide derivatives were designed, synthesized and their biological activities were evaluated against PTP1B and Scr homology-2 domain containing protein tyrosine phosphatase-2 (SHP2). Among them, compound 3c displayed moderate inhibitory activity with IC50 of (5.13±0.21) μmol/L against PTP1B and showed two times selectivity for other related PTPs. Interestingly, compound 12[IC50=(7.47±1.26) μmol/L] showed moderate inhibitory activity against SHP2 and 2-fold selectivity against PTP1B, T-cell protein tyrosine phosphatase (TCPTP) or Src homology-2 domain containing protein tyrosine phosphatase-1 (SHP1) respectively, and offered a novel scaffold to develop new SHP2 inhibitors.
To explore the chemical space of protein tyrosine phosphatase 1B (PTP1B) inhibitors by changing bis-aromatic amide moiety into aromatic amide moiety, a series of aromatic amide derivatives were designed, synthesized and their biological activities were evaluated against PTP1B and Scr homology-2 domain containing protein tyrosine phosphatase-2 (SHP2). Among them, compound 3c displayed moderate inhibitory activity with IC50 of (5.13±0.21) μmol/L against PTP1B and showed two times selectivity for other related PTPs. Interestingly, compound 12[IC50=(7.47±1.26) μmol/L] showed moderate inhibitory activity against SHP2 and 2-fold selectivity against PTP1B, T-cell protein tyrosine phosphatase (TCPTP) or Src homology-2 domain containing protein tyrosine phosphatase-1 (SHP1) respectively, and offered a novel scaffold to develop new SHP2 inhibitors.
2016, 36(9): 2150-2156
doi: 10.6023/cjoc201603047
Abstract:
The method to synthesize 5-aminotetrazoles starting from 1, 3-disubtituted selenoureas using ion-supported hypervalent iodine(Ⅲ) reagent and sodium azide via electrocyclization has been discovered. The reaction has some advantages, such as using green and recyclable reagent[dibmim]+[PF6]-, environmental benign, short reaction time, good selectivity and high yield. The reaction is in line with the requirements of green chemistry.
The method to synthesize 5-aminotetrazoles starting from 1, 3-disubtituted selenoureas using ion-supported hypervalent iodine(Ⅲ) reagent and sodium azide via electrocyclization has been discovered. The reaction has some advantages, such as using green and recyclable reagent[dibmim]+[PF6]-, environmental benign, short reaction time, good selectivity and high yield. The reaction is in line with the requirements of green chemistry.
2016, 36(9): 2157-2161
doi: 10.6023/cjoc201604030
Abstract:
An efficient method for the preparation of (4S, 5R)-4-(tert-butyldimethylsilyloxy)-5-methylpyrrolidin-2-one (1) by an addition-cyclization-deprotection process of the imine (R, SRS)-8 with Grignard reagent is described. (2S, 3S)-Nemonapride, a commercial antipsychotics, was asymmetrically synthesized by a concise and effective route involving above one-pot intramo-lecular tandem protocol in 17% overall yield from 8.
An efficient method for the preparation of (4S, 5R)-4-(tert-butyldimethylsilyloxy)-5-methylpyrrolidin-2-one (1) by an addition-cyclization-deprotection process of the imine (R, SRS)-8 with Grignard reagent is described. (2S, 3S)-Nemonapride, a commercial antipsychotics, was asymmetrically synthesized by a concise and effective route involving above one-pot intramo-lecular tandem protocol in 17% overall yield from 8.
2016, 36(9): 2162-2167
doi: 10.6023/cjoc201603001
Abstract:
For the purpose of quality control of demethylphenidate hydrochloride (1a), three related optical substances were synthesized and characterized. (S, S)-Methylphenidate hydrochloride (1b), (R, S)-methylphenidate hydrochloride (1c) and (S, R)-methylphenidate hydrochloride (1d) were synthesized via the same route with demethylphenidate hydrochloride but changing different intermediates or resolving agents. The structures of four optical isomers were tested by MS and NMR spectra, the chemical and optical purities were analyzed by HPLC spectra, the specific rotation values were also measured, the absolute configurations of compounds 1a and 1d were confirmed by X-ray study. The three optical isomers can be used as the reference substances of the related optical substances in the quality control of demethylphenidate hydrochloride.
For the purpose of quality control of demethylphenidate hydrochloride (1a), three related optical substances were synthesized and characterized. (S, S)-Methylphenidate hydrochloride (1b), (R, S)-methylphenidate hydrochloride (1c) and (S, R)-methylphenidate hydrochloride (1d) were synthesized via the same route with demethylphenidate hydrochloride but changing different intermediates or resolving agents. The structures of four optical isomers were tested by MS and NMR spectra, the chemical and optical purities were analyzed by HPLC spectra, the specific rotation values were also measured, the absolute configurations of compounds 1a and 1d were confirmed by X-ray study. The three optical isomers can be used as the reference substances of the related optical substances in the quality control of demethylphenidate hydrochloride.
2016, 36(9): 2168-2174
doi: 10.6023/cjoc201603004
Abstract:
The hydrophosphonylation of aldehydes/ketones was explored by use of seven bis(β-diketiminato) lanthanide(Ⅱ) complexes[Eu(L2, 6-ipr2)2·CH3C6H5, L2, 6-ipr2=[N(2, 6-iPr2C6H3)C(Me)]2CH- (1); Eu(L2, 6-Me2)2(THF), L2, 6-Me2=[N(2, 6-Me2C6H3)C(Me)]2CH- (2); Eu(L2, 4, 6-Me3)2(THF), L2, 4, 6-Me3=[N(2, 4, 6-Me3C6H2)C(Me)]2CH- (3); Eu(LPh2, 6-ipr2)2, LPh2, 6-ipr2=[(2, 6-iPr2C6H3)NC(Me)CHC(Me)N(C6H5)]-(4); Sm(L2, 6-ipr2)2·CH3C6H5 (5); Yb(LPh2, 6-ipr2)2 (6); Yb(L2-Me)2(THF), L2-Me=[N(2-MeC6H4)C(Me)]2CH- (7)] as the catalysts. All complexes were found to be able to catalyze the hydrophosphonylation between aromatic or heterecycle aldehyde and diethyl phosphite with high activity under wild conditions. All the reactions gave the products in 90%~99% yields using 0.08 mol% of complex 7 at 25℃ under solvent-free. The catalyst activity was found to depend on the β-diketiminato ligands with the sequence of L2, 6-Me2 < L2, 4, 6-Me3 < L2, 6-ipr2≈LPh2, 6-ipr2. This catalyst system showed a wide scope of aldehydes. Besides, bis(β-diketiminato) lanthanide(Ⅱ) complexes could also efficiently catalyze the hy-drophosphonylation of unactive ketones with diethyl phosphite and showed a good substrate scope.
The hydrophosphonylation of aldehydes/ketones was explored by use of seven bis(β-diketiminato) lanthanide(Ⅱ) complexes[Eu(L2, 6-ipr2)2·CH3C6H5, L2, 6-ipr2=[N(2, 6-iPr2C6H3)C(Me)]2CH- (1); Eu(L2, 6-Me2)2(THF), L2, 6-Me2=[N(2, 6-Me2C6H3)C(Me)]2CH- (2); Eu(L2, 4, 6-Me3)2(THF), L2, 4, 6-Me3=[N(2, 4, 6-Me3C6H2)C(Me)]2CH- (3); Eu(LPh2, 6-ipr2)2, LPh2, 6-ipr2=[(2, 6-iPr2C6H3)NC(Me)CHC(Me)N(C6H5)]-(4); Sm(L2, 6-ipr2)2·CH3C6H5 (5); Yb(LPh2, 6-ipr2)2 (6); Yb(L2-Me)2(THF), L2-Me=[N(2-MeC6H4)C(Me)]2CH- (7)] as the catalysts. All complexes were found to be able to catalyze the hydrophosphonylation between aromatic or heterecycle aldehyde and diethyl phosphite with high activity under wild conditions. All the reactions gave the products in 90%~99% yields using 0.08 mol% of complex 7 at 25℃ under solvent-free. The catalyst activity was found to depend on the β-diketiminato ligands with the sequence of L2, 6-Me2 < L2, 4, 6-Me3 < L2, 6-ipr2≈LPh2, 6-ipr2. This catalyst system showed a wide scope of aldehydes. Besides, bis(β-diketiminato) lanthanide(Ⅱ) complexes could also efficiently catalyze the hy-drophosphonylation of unactive ketones with diethyl phosphite and showed a good substrate scope.
2016, 36(9): 2175-2182
doi: 10.6023/cjoc201603005
Abstract:
Benzimidazoles derived from chiral amino acids and benzimidazoles derived from dipeptides were prepared and proved to be efficient ligands in the ruthenium catalyzed asymmetric transfer hydrogenation of acetophenone. Employing ligand 2 in the reduction of acetophenone resulted in better activity and enantioselectivity (with 15400 h-1 TOF and 77% ee). Through structure-activity correlations, the corresponding metal-ligand bifunctional mechanism was speculated. In addition, the catalytic system of[RuCl2(p-cymene)]2/2 exhibited reversed temperature effects, which explained through kinetics data. The enantioselectivity was increased from 38% to 43% when LiCl was added in dipeptides derived benzimidazoles 7/[RuCl2(p-cymene)]2 catalyzed asymmetric transfer hydrogenation.
Benzimidazoles derived from chiral amino acids and benzimidazoles derived from dipeptides were prepared and proved to be efficient ligands in the ruthenium catalyzed asymmetric transfer hydrogenation of acetophenone. Employing ligand 2 in the reduction of acetophenone resulted in better activity and enantioselectivity (with 15400 h-1 TOF and 77% ee). Through structure-activity correlations, the corresponding metal-ligand bifunctional mechanism was speculated. In addition, the catalytic system of[RuCl2(p-cymene)]2/2 exhibited reversed temperature effects, which explained through kinetics data. The enantioselectivity was increased from 38% to 43% when LiCl was added in dipeptides derived benzimidazoles 7/[RuCl2(p-cymene)]2 catalyzed asymmetric transfer hydrogenation.
2016, 36(9): 2183-2190
doi: 10.6023/cjoc201603023
Abstract:
A series of new isolongifolanonyl pyrazole derivatives 3a~3j were synthesized by aldol-condensation, cyclization and dehydroaromatization from isolongifolanone. The yields of products ranged from 69.5% to 76.5%. The chemical structures of compounds obtained were elucidated by 1H NMR, 13C NMR, IR, MS spectra and elemental analysis. The strucure of compound 3i was determined by X-ray single crystal diffraction. Their inhibitory activities against human hepatoma cell (HepG2) and human umbilical vein endothelial cell (HUVECs) were evaluated. The results indicated that compounds 3h and 3i[IC50=(15.42±0.6), (4.74±0.3) μmol/L] showed obvious inhibitory activity against HUVECs. Compounds 3a, 3c, 3e and 3j[IC50=(5.27±0.5), (6.71±0.4), (4.68±0.2), (4.57±0.5)] μmol/L showed better antitumor activity against HepG2.
A series of new isolongifolanonyl pyrazole derivatives 3a~3j were synthesized by aldol-condensation, cyclization and dehydroaromatization from isolongifolanone. The yields of products ranged from 69.5% to 76.5%. The chemical structures of compounds obtained were elucidated by 1H NMR, 13C NMR, IR, MS spectra and elemental analysis. The strucure of compound 3i was determined by X-ray single crystal diffraction. Their inhibitory activities against human hepatoma cell (HepG2) and human umbilical vein endothelial cell (HUVECs) were evaluated. The results indicated that compounds 3h and 3i[IC50=(15.42±0.6), (4.74±0.3) μmol/L] showed obvious inhibitory activity against HUVECs. Compounds 3a, 3c, 3e and 3j[IC50=(5.27±0.5), (6.71±0.4), (4.68±0.2), (4.57±0.5)] μmol/L showed better antitumor activity against HepG2.
2016, 36(9): 2191-2196
doi: 10.6023/cjoc201603032
Abstract:
An easy and efficient new method for the three-component synthesis of 2-oxazolines from ethyl α-cyanocinnamate derivatives with amide and N-bromosuccinimide has been developed. A series of ethyl α-cyanocinnamate derivatives can be smoothly con-verted into corresponding 2-oxazoline derivatives promoted by Na2CO3 in N, N-dimethylformamide (DMF) at room temperature in high yield (up to 94%). The reactions of 11 structurally different substrates with propionamide, acrylamide, isobutyamide and pentanamide were investigated, respectively. The results indicated that the protocol has applicability in a large scope of ethyl α-cyanocinnamate derivatives and amides. A possible mechanism was proposed and it can explain well the full regiospecificity of the reaction. 39 new compounds were achieved via the three-component synthesis reaction and all the products structures were confirmed by their 1H NMR, 13C NMR and HRMS analysis.
An easy and efficient new method for the three-component synthesis of 2-oxazolines from ethyl α-cyanocinnamate derivatives with amide and N-bromosuccinimide has been developed. A series of ethyl α-cyanocinnamate derivatives can be smoothly con-verted into corresponding 2-oxazoline derivatives promoted by Na2CO3 in N, N-dimethylformamide (DMF) at room temperature in high yield (up to 94%). The reactions of 11 structurally different substrates with propionamide, acrylamide, isobutyamide and pentanamide were investigated, respectively. The results indicated that the protocol has applicability in a large scope of ethyl α-cyanocinnamate derivatives and amides. A possible mechanism was proposed and it can explain well the full regiospecificity of the reaction. 39 new compounds were achieved via the three-component synthesis reaction and all the products structures were confirmed by their 1H NMR, 13C NMR and HRMS analysis.
2016, 36(9): 2197-2203
doi: 10.6023/cjoc201601005
Abstract:
In this work, novel organic non-linear optical chromophore containing azo-furan based conjugation bridge (EFNFC) was designed and synthesized. Moreover, the optical and thermal properties of EFNFC were systematically compared with those of two different conjugation bridges of vinyl-furan (EFFC) and azo-benzene (EFNC) containing same electron donor and acceptor moieties, respectively. It was found that similar maximum absorption wavelength in DMSO solution was detected for EFNFC (573 nm) and EFNC (568 nm), which indicated an improved visible light transmittance compared to EFFC. Meanwhile, the second-order polarizability of EFNFC (4.479×10-49 esu) was lower than that of EFNC (5.971×10-49 esu), but larger than that of EFFC (3.194×10-49 esu) according to the solvatochromism test. All three chromophores exhibited good thermal stability as their 5% decomposition temperatures (Td) were over 250℃, especially the highest Td of 275℃ was detected from the synthesized novel EFNFC chromophore.
In this work, novel organic non-linear optical chromophore containing azo-furan based conjugation bridge (EFNFC) was designed and synthesized. Moreover, the optical and thermal properties of EFNFC were systematically compared with those of two different conjugation bridges of vinyl-furan (EFFC) and azo-benzene (EFNC) containing same electron donor and acceptor moieties, respectively. It was found that similar maximum absorption wavelength in DMSO solution was detected for EFNFC (573 nm) and EFNC (568 nm), which indicated an improved visible light transmittance compared to EFFC. Meanwhile, the second-order polarizability of EFNFC (4.479×10-49 esu) was lower than that of EFNC (5.971×10-49 esu), but larger than that of EFFC (3.194×10-49 esu) according to the solvatochromism test. All three chromophores exhibited good thermal stability as their 5% decomposition temperatures (Td) were over 250℃, especially the highest Td of 275℃ was detected from the synthesized novel EFNFC chromophore.
2016, 36(9): 2204-2211
doi: 10.6023/cjoc201601018
Abstract:
A pyrene derivative PYPA, namely, 1-(pyren-1-yl)-N, N-bis(pyridin-2-ylmethyl)methanamine (PYPA), was synthesized to develop a chemosensor. The studies show that PYPA exhibits high sensitivity and selectivity toward Zn2+ over many other metal cations in the presence of pyrophosphatic acid (PPi). It has a low detection limit of 0.030 nmol/L. Detection of Zn2+ was not interfered by various cations or anions. In the presence of PPi, over a 8-fold fluorescence enhancement at 383 nm was observed within 20 s. Cell studies further demonstrated that PYPA can be a potential probe to detect Zn2+ in human liver cells (L-02).
A pyrene derivative PYPA, namely, 1-(pyren-1-yl)-N, N-bis(pyridin-2-ylmethyl)methanamine (PYPA), was synthesized to develop a chemosensor. The studies show that PYPA exhibits high sensitivity and selectivity toward Zn2+ over many other metal cations in the presence of pyrophosphatic acid (PPi). It has a low detection limit of 0.030 nmol/L. Detection of Zn2+ was not interfered by various cations or anions. In the presence of PPi, over a 8-fold fluorescence enhancement at 383 nm was observed within 20 s. Cell studies further demonstrated that PYPA can be a potential probe to detect Zn2+ in human liver cells (L-02).
2016, 36(9): 2212-2215
doi: 10.6023/cjoc201602036
Abstract:
The cycloaddition reaction of a suitably substituted indolyl benzylic alcohol with an ethyl 3-indoleacrylate catalyzed by phos-phoric acids derived from (S)-BINOL was described. When the chiral phosphoric acid bearing α-naphthyl at 3, 3'-positions of the binaphthyl was used as a catalyst, pyrrolo[1, 2-a]indole derivatives with three contiguous stereocenters were obtained in high yield up to 91%, with good to high diastereoselectivity (9/1~20/1 dr) and enantioselectivity (62%~92% ee for the major dia-stereoisomer).
The cycloaddition reaction of a suitably substituted indolyl benzylic alcohol with an ethyl 3-indoleacrylate catalyzed by phos-phoric acids derived from (S)-BINOL was described. When the chiral phosphoric acid bearing α-naphthyl at 3, 3'-positions of the binaphthyl was used as a catalyst, pyrrolo[1, 2-a]indole derivatives with three contiguous stereocenters were obtained in high yield up to 91%, with good to high diastereoselectivity (9/1~20/1 dr) and enantioselectivity (62%~92% ee for the major dia-stereoisomer).
2016, 36(9): 2216-2219
doi: 10.6023/cjoc201603038
Abstract:
Investigation on Swertia mussotii resulted in four compounds by means of various chromatographic techniques (silica gel, Sephadex LH-20, RP-LC and Pre-HPLC). Their structures were determined as (S, 2E, 6E)-4, 8-dihydroxy-2, 6-dime-thylocta-2, 6-dienoic acid (1), (S, 2E, 6E)-8-(formyloxy)-4-hydroxy-2, 6-dimethylocta-2, 6-dienoic acid (2), swerimilegenins B and C (3 and 4) on the basis of extensive spectroscopic analyses including MS, IR, UV, 1D-and 2D-NMR. Among them, compounds 1 and 2 are two new linear monoterpenoids named as swerimusic acids C (1) and D (2), compounds 3 and 4 are two unusual known secoiridoid aglycones of C9-skeleton obtained for the first time from this plant. Compounds 1~4 were evaluated for their anti-Hepatitis B Virus (HBV) activities on HepG2.2.15 cells line in vitro, but these compounds showed no anti-HBV activity at the maximal tesing concentration. Herin, we only report the isolation and structure elucidation of these compounds.
Investigation on Swertia mussotii resulted in four compounds by means of various chromatographic techniques (silica gel, Sephadex LH-20, RP-LC and Pre-HPLC). Their structures were determined as (S, 2E, 6E)-4, 8-dihydroxy-2, 6-dime-thylocta-2, 6-dienoic acid (1), (S, 2E, 6E)-8-(formyloxy)-4-hydroxy-2, 6-dimethylocta-2, 6-dienoic acid (2), swerimilegenins B and C (3 and 4) on the basis of extensive spectroscopic analyses including MS, IR, UV, 1D-and 2D-NMR. Among them, compounds 1 and 2 are two new linear monoterpenoids named as swerimusic acids C (1) and D (2), compounds 3 and 4 are two unusual known secoiridoid aglycones of C9-skeleton obtained for the first time from this plant. Compounds 1~4 were evaluated for their anti-Hepatitis B Virus (HBV) activities on HepG2.2.15 cells line in vitro, but these compounds showed no anti-HBV activity at the maximal tesing concentration. Herin, we only report the isolation and structure elucidation of these compounds.
2016, 36(9): 2220-2224
doi: 10.6023/cjoc201605023
Abstract:
Polymerization-induced self-assembly (PISA) is a new robust strategy to produce concentrated dispersions of block copolymer nano-objects. Insight into the dynamic process can promote the development of PISA by computer simulations. In this work, dissipative particle dynamics simulations (DPD) with a reaction model were employed to investigate the PISA behavior of ABC triblock copolymer. The polymerization of solvophobic B block was firstly performed using solvophilic macromolecular initiator A to fabricate AB copolymer. The continuous morphology transition from spherical micelle to wormlike micelle, to lamellae and finally to vesicle was observed during the process. Then, the polymerization of C block was further carried out and induced the different ABC triblock copolymer aggregates by tuning the interaction between C block and solvent (solvophobic or solvophilic).
Polymerization-induced self-assembly (PISA) is a new robust strategy to produce concentrated dispersions of block copolymer nano-objects. Insight into the dynamic process can promote the development of PISA by computer simulations. In this work, dissipative particle dynamics simulations (DPD) with a reaction model were employed to investigate the PISA behavior of ABC triblock copolymer. The polymerization of solvophobic B block was firstly performed using solvophilic macromolecular initiator A to fabricate AB copolymer. The continuous morphology transition from spherical micelle to wormlike micelle, to lamellae and finally to vesicle was observed during the process. Then, the polymerization of C block was further carried out and induced the different ABC triblock copolymer aggregates by tuning the interaction between C block and solvent (solvophobic or solvophilic).
2016, 36(9): 2225-2231
doi: 10.6023/cjoc201603026
Abstract:
Alkyl multisubstituted pyridine-2-yl sulfones have been designed and synthesized from 6-alkylthiopyridine using H2O2 and NaWO3·2H2O as catalysts in N, N-dimethylformamide (DMF). A series of new 6-alkoxy(aryloxy) multisubstituted pyridine derivatives have been synthesized from alkyl multisubstituted pyridine-2-yl sulfone and alcohol or phenol using K2CO3 (NaOC2H5 or NaOCH3) as catalyst in CH3CN. The structures of target compounds have been confirmed by 1H NMR, 13C NMR, EI-MS, IR spectroscopy and elemental analysis. The structure of 4-amino-5-cyano-2-methyl-6-(3-nitryl phenoxy) nicotinic acid methyl ester has been determined by single crystal X-ray diffraction. The results of preliminary bioassay indicated that some compounds possess moderate herbicidal activities against the rape and barnyard grass and show obvious selectivity.
Alkyl multisubstituted pyridine-2-yl sulfones have been designed and synthesized from 6-alkylthiopyridine using H2O2 and NaWO3·2H2O as catalysts in N, N-dimethylformamide (DMF). A series of new 6-alkoxy(aryloxy) multisubstituted pyridine derivatives have been synthesized from alkyl multisubstituted pyridine-2-yl sulfone and alcohol or phenol using K2CO3 (NaOC2H5 or NaOCH3) as catalyst in CH3CN. The structures of target compounds have been confirmed by 1H NMR, 13C NMR, EI-MS, IR spectroscopy and elemental analysis. The structure of 4-amino-5-cyano-2-methyl-6-(3-nitryl phenoxy) nicotinic acid methyl ester has been determined by single crystal X-ray diffraction. The results of preliminary bioassay indicated that some compounds possess moderate herbicidal activities against the rape and barnyard grass and show obvious selectivity.
2016, 36(9): 2236-2241
doi: 10.6023/cjoc201602023
Abstract:
Reaction of 7-amino-6-nitro[1, 2, 5]oxadiazolo[3, 4-b]pyridine-1-oxide (1, namely pyridofuroxan) with ammonia or/and amines under mild conditions let to the corresponding 5-nitro-3-nitroso-2, 4-diaminopyridine 5a~5f. It is shown that the ring-opening reactivity of pyridofuroxan 1 was significantly affected by the 6-nitro substituent. The structures of all target compounds were identified by 1H NMR, 13C NMR and HRMS. The biological evaluation was performed on human lung cancer cell line (H522) and glioma cell line (U87) by 3-(4, 5-dimethylthigal-2-yl)-2, 5-(diphenyltetragalium) bromide (MTT) assay. The results suggested that all of the target compounds exhibited potent anti-tumor activities in vitro.
Reaction of 7-amino-6-nitro[1, 2, 5]oxadiazolo[3, 4-b]pyridine-1-oxide (1, namely pyridofuroxan) with ammonia or/and amines under mild conditions let to the corresponding 5-nitro-3-nitroso-2, 4-diaminopyridine 5a~5f. It is shown that the ring-opening reactivity of pyridofuroxan 1 was significantly affected by the 6-nitro substituent. The structures of all target compounds were identified by 1H NMR, 13C NMR and HRMS. The biological evaluation was performed on human lung cancer cell line (H522) and glioma cell line (U87) by 3-(4, 5-dimethylthigal-2-yl)-2, 5-(diphenyltetragalium) bromide (MTT) assay. The results suggested that all of the target compounds exhibited potent anti-tumor activities in vitro.
2016, 36(9): 2242-2246
doi: 10.6023/cjoc201601045
Abstract:
Two methods of catalytic asymmetric synthesis of (S)-3, 5-dibromophenylalanine are presented. One approach is to use asymmetric alkylation reaction starting from diphenylimine glycine tert-butyl ester and 3, 5-dibromobenzyl bromide, with O-allyl-N-9-anthracene methyl bromide cinchonidine as phase-transfer catalyst, the (S)-3, 5-dibromophenylalanine derivative was obtained (up to 94.9% ee). The optimized conditions of asymmetric phase transfer catalytic alkylation are explored. Another method is to employ asymmetric hydrogenation starting from 2-acetylamino-3-(3, 5-dibromophenyl)acrylic acid with bis(1, 5-cyclooctadiene)rhodium(I) trifluoromethanesulfonate and (R)-diphenylphosphino-N-methyl-1-[(S)-2-diphenyl-phos-phino)ferrocenyl]ethylamine[(R)-methyl BoPhoz] as chiral catalyst. (S)-3, 5-Dibromophenylalanine hydrochloride was obtained after hydrolysis. By Fmoc protection, Fmoc-(S)-3, 5-dibromophenylalanine was obtained (up to 94.7% ee). By comparison of the two methods, the first one gives higher overall yield and a little bit better selectivity, and is more suitable for the synthesis of other chiral dihalo-substituented phenylalanine derivatives.
Two methods of catalytic asymmetric synthesis of (S)-3, 5-dibromophenylalanine are presented. One approach is to use asymmetric alkylation reaction starting from diphenylimine glycine tert-butyl ester and 3, 5-dibromobenzyl bromide, with O-allyl-N-9-anthracene methyl bromide cinchonidine as phase-transfer catalyst, the (S)-3, 5-dibromophenylalanine derivative was obtained (up to 94.9% ee). The optimized conditions of asymmetric phase transfer catalytic alkylation are explored. Another method is to employ asymmetric hydrogenation starting from 2-acetylamino-3-(3, 5-dibromophenyl)acrylic acid with bis(1, 5-cyclooctadiene)rhodium(I) trifluoromethanesulfonate and (R)-diphenylphosphino-N-methyl-1-[(S)-2-diphenyl-phos-phino)ferrocenyl]ethylamine[(R)-methyl BoPhoz] as chiral catalyst. (S)-3, 5-Dibromophenylalanine hydrochloride was obtained after hydrolysis. By Fmoc protection, Fmoc-(S)-3, 5-dibromophenylalanine was obtained (up to 94.7% ee). By comparison of the two methods, the first one gives higher overall yield and a little bit better selectivity, and is more suitable for the synthesis of other chiral dihalo-substituented phenylalanine derivatives.
