A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of t...A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of the metal catalyst before the stereo-determining step.Herein,we report a chiral dirhodium(Ⅱ)-catalyzed asymmetric annulation of vinyl diazoesters withα-hydroxyl ketones,which provides an efficient way to form chiral 2,3-dihydropyrans in good yields with excellent diastereoselectivities and enantioselectivities.This article is the first example of the chiral dirhodium complex–controlled asymmetric aldol-type interception of an in situ–formed oxonium ylide.The origin of the high stereoselectivity is well expounded via experimental and computational studies.These generated chiral products exhibit potent antiproliferation activity in three tested cancer cell lines,namely HCT116(colon cancer),A549(lung adenocarcinoma),and SJSA-1(osteosarcoma cancer).展开更多
A practical approach to the asymmetric synthesis of the ring A substructure of genkwadane A, a daphnane diterpenoid, was developed. This synthesis features the Mukaiyama aldol reaction to introduce the quaternary ster...A practical approach to the asymmetric synthesis of the ring A substructure of genkwadane A, a daphnane diterpenoid, was developed. This synthesis features the Mukaiyama aldol reaction to introduce the quaternary stereogenic center at C4 and VO（acac）2-catalyzed Jackson-Ellman-Bolrn sulfoxidation to deliver the corresponding sulfoxide. The Dieckmann-type condensation was efficiently promoted by KHMDS and the ring A substructure was finally accomplished through Barton iodination condition.展开更多
A facile route to 2-benzylthio-5-phenyl-3,4-disubstituted thiophenes was described. Catalyzed by sodium hydroxide, the title compounds were synthesized in moderate to good yields simply from the intramolecular aldol t...A facile route to 2-benzylthio-5-phenyl-3,4-disubstituted thiophenes was described. Catalyzed by sodium hydroxide, the title compounds were synthesized in moderate to good yields simply from the intramolecular aldol type condensation of α-oxo ketene dibenzylthioacetals. The chemical selectivity for this annulation reaction was studied and discussed.展开更多
基金supported by the National Natural Science Foundation of China(22001268,21973113,81973176)the Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery(2019B030301005)+2 种基金the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(2016ZT06Y337)the Guangdong Natural Science Fund(2020A1515010614)Key-Area Research and Development Program of Guangdong Province(2022B1111050003)。
文摘A chiral dirhodium complex is an effective and robust catalyst for asymmetric carbene transformations.However,dirhodiumcatalyzed asymmetric ylide interception processes are rare,mainly because of the dissociation of the metal catalyst before the stereo-determining step.Herein,we report a chiral dirhodium(Ⅱ)-catalyzed asymmetric annulation of vinyl diazoesters withα-hydroxyl ketones,which provides an efficient way to form chiral 2,3-dihydropyrans in good yields with excellent diastereoselectivities and enantioselectivities.This article is the first example of the chiral dirhodium complex–controlled asymmetric aldol-type interception of an in situ–formed oxonium ylide.The origin of the high stereoselectivity is well expounded via experimental and computational studies.These generated chiral products exhibit potent antiproliferation activity in three tested cancer cell lines,namely HCT116(colon cancer),A549(lung adenocarcinoma),and SJSA-1(osteosarcoma cancer).
文摘A practical approach to the asymmetric synthesis of the ring A substructure of genkwadane A, a daphnane diterpenoid, was developed. This synthesis features the Mukaiyama aldol reaction to introduce the quaternary stereogenic center at C4 and VO（acac）2-catalyzed Jackson-Ellman-Bolrn sulfoxidation to deliver the corresponding sulfoxide. The Dieckmann-type condensation was efficiently promoted by KHMDS and the ring A substructure was finally accomplished through Barton iodination condition.
文摘A facile route to 2-benzylthio-5-phenyl-3,4-disubstituted thiophenes was described. Catalyzed by sodium hydroxide, the title compounds were synthesized in moderate to good yields simply from the intramolecular aldol type condensation of α-oxo ketene dibenzylthioacetals. The chemical selectivity for this annulation reaction was studied and discussed.
