An efficient and mild protocol for bromination of aryl azides with N-bromosuccinimide(NBS) under FeCl_3 catalysis in 1,2- dichloroethane was developed.It is proved to be an efficient method for obtaining brominated ...An efficient and mild protocol for bromination of aryl azides with N-bromosuccinimide(NBS) under FeCl_3 catalysis in 1,2- dichloroethane was developed.It is proved to be an efficient method for obtaining brominated aryl azides.展开更多
An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide(NBS) in the presence of K3PO4 was developed. The reaction was performed smo...An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide(NBS) in the presence of K3PO4 was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields(up to 95%) in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of a-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition- cyclization pathway was proposed.展开更多
A novel and convenient way has been developed for the preparation of bromoallenes from propargyl alcohols by the reagent combination of N-bromosuccinimide and dimethyl sulfide. Bromoallenes with high regioselectivity ...A novel and convenient way has been developed for the preparation of bromoallenes from propargyl alcohols by the reagent combination of N-bromosuccinimide and dimethyl sulfide. Bromoallenes with high regioselectivity were obtained in a convenient method.展开更多
A facile transformation of alkynes into α-amino ketones by an N-bromosuccinimide-mediated one-pot cascade strategy is described. A variety of α-amino ketones are obtained in moderate to good yields under mild condit...A facile transformation of alkynes into α-amino ketones by an N-bromosuccinimide-mediated one-pot cascade strategy is described. A variety of α-amino ketones are obtained in moderate to good yields under mild conditions. To overcome the multi-step synthesis, N-bromosuccinimide is involved in multiple tasks, playing a key role in the reaction course.展开更多
A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.
Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^* to gain a deeper insight into the nature of the N--Br haloge...Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^* to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 ( sp^3 ) 〉 0 ( sp^2 ), which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.展开更多
A highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides. The present process...A highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides. The present process enables the use of two RS in RSSR and shows broad functional group tolerance, which represents an atom-economical and practical procedure for the synthesis of thiosulfonates. A plausible mechanism for the role of NBS as a promoter for the cleavage of disulfides generating N-(organothio)succinimide that then undergos facile sulenylation with sulfinates is proposed.展开更多
An efficient dual stereocontrot in iridium-catalyzed hydrogenation of 1-substituted 3,4-dihydroisoquinolines was realized by tuning the amount of N-bromosuccinimide using chiral ligand of single configuration, providi...An efficient dual stereocontrot in iridium-catalyzed hydrogenation of 1-substituted 3,4-dihydroisoquinolines was realized by tuning the amount of N-bromosuccinimide using chiral ligand of single configuration, providing both enantiomers of 1-substituted 1,2,3,4-tetrahydroisoquinolines with up to 89% ee (S) and 98% ee*(R), respectively. Dual activation role of N-bromosuccinimide is proposed to be responsible for the reversal of enantioselectivity under two hydrogenation conditions.展开更多
An efficient and facile approach for tetrachlorosilane as an in situ mediated transformation via a one-pot, synthesis of vicinal bromoazides through the generation of BrN3 from azidochlorosilane and N-bromosuccinimide...An efficient and facile approach for tetrachlorosilane as an in situ mediated transformation via a one-pot, synthesis of vicinal bromoazides through the generation of BrN3 from azidochlorosilane and N-bromosuccinimide in acetonitrile as solvent at ambient temperature is achieved. This catalytic process represents a highly regioselective and high yielding method for the synthesis of 1,2- bromoazides. Thiamine pyrophosphate (TPP) riboswitches regulate essential genes in bacteria by changing conformation upon binding intracellular TPP. Molecular docking studies are conducted to understand the orientation and the interaction of each synthesized molecules with TPP riboswitches, 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academv of Medical Sciences.展开更多
基金supported by National Natural Science Foundation of China(No30873153)the Key Projects of Shanghai in Biomedical(No08431902700)the Scientific Research Foundation of State Education Ministry for the Returned Overseas Chinese Scholars
文摘An efficient and mild protocol for bromination of aryl azides with N-bromosuccinimide(NBS) under FeCl_3 catalysis in 1,2- dichloroethane was developed.It is proved to be an efficient method for obtaining brominated aryl azides.
基金Supported by the National Natural Science Foundation of China(Nos.20572066, 20906059) and the Natural Science Founda- tion of Shaanxi Province of China(No .2009JM2011).
文摘An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide(NBS) in the presence of K3PO4 was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields(up to 95%) in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of a-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition- cyclization pathway was proposed.
基金the Fundamental Research Funds for the Central Universities(No.DUT12LK07).Dr.Bao thanks financial support from the Fundamental Research Funds for the Central Universities(No. DUT11SM01)
文摘A novel and convenient way has been developed for the preparation of bromoallenes from propargyl alcohols by the reagent combination of N-bromosuccinimide and dimethyl sulfide. Bromoallenes with high regioselectivity were obtained in a convenient method.
基金the Natural Science Foundation of Xinjiang Province(No. 2016D01C009)the Educational Commission of Xinjiang(No. XJEDU2017S053)for financial support
文摘A facile transformation of alkynes into α-amino ketones by an N-bromosuccinimide-mediated one-pot cascade strategy is described. A variety of α-amino ketones are obtained in moderate to good yields under mild conditions. To overcome the multi-step synthesis, N-bromosuccinimide is involved in multiple tasks, playing a key role in the reaction course.
文摘A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.
基金Supported by the National Natural Science Foundation of China(No20502022)the Natural Science Foundation of Zhe-jiang Province(NoY406374)
文摘Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^* to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 ( sp^3 ) 〉 0 ( sp^2 ), which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.
基金Supporting intbrmation tbr this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201200028 or from the author.Acknowledgement This work was supported by the National Natural Science Foundation of China (Nos. 21102105 and 21072153).
文摘A highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides. The present process enables the use of two RS in RSSR and shows broad functional group tolerance, which represents an atom-economical and practical procedure for the synthesis of thiosulfonates. A plausible mechanism for the role of NBS as a promoter for the cleavage of disulfides generating N-(organothio)succinimide that then undergos facile sulenylation with sulfinates is proposed.
基金We are grateful for the financial support from the National Natural Science Foundation of China (Nos. 21472188, 21690074),the State Key Laboratory of Fine Chemicals (No. KF1503) and the Youth Innovation Promotion Association of Chinese Academy of Sciences (No, 2014167).
文摘An efficient dual stereocontrot in iridium-catalyzed hydrogenation of 1-substituted 3,4-dihydroisoquinolines was realized by tuning the amount of N-bromosuccinimide using chiral ligand of single configuration, providing both enantiomers of 1-substituted 1,2,3,4-tetrahydroisoquinolines with up to 89% ee (S) and 98% ee*(R), respectively. Dual activation role of N-bromosuccinimide is proposed to be responsible for the reversal of enantioselectivity under two hydrogenation conditions.
文摘An efficient and facile approach for tetrachlorosilane as an in situ mediated transformation via a one-pot, synthesis of vicinal bromoazides through the generation of BrN3 from azidochlorosilane and N-bromosuccinimide in acetonitrile as solvent at ambient temperature is achieved. This catalytic process represents a highly regioselective and high yielding method for the synthesis of 1,2- bromoazides. Thiamine pyrophosphate (TPP) riboswitches regulate essential genes in bacteria by changing conformation upon binding intracellular TPP. Molecular docking studies are conducted to understand the orientation and the interaction of each synthesized molecules with TPP riboswitches, 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academv of Medical Sciences.