A highly stereoselective catalytic alkylation sequence for the synthesis of highly functionalized and versatile five-membered-ring compounds bearing all-carbon quaternary stereocenters was developed. Enantioselective desymmetrization of achiral cyclopentene-1,3-diones was thus executed by chiral Cu-phosphoramidite catalysts. A variety of complicated cyclopentane derivatives can be synthesized with
Chiral N-Heterocyclic-Carbene-Catalyzed Cascade Asymmetric Desymmetrization of Cyclopentenediones with Enals: Access to Optically Active 1,3-Indandione Derivatives
作者:Jia-Ming Hu、Jun-Qi Zhang、Bing-Bing Sun、Jun-Bo Chen、Jie-Qiang Yu、Xiao-Peng Yang、Hao-Peng Lv、Zheng Wang、Xing-Wang Wang
DOI:10.1021/acs.orglett.9b03178
日期:2019.11.1
A chiral N-heterocyclic-carbene-catalyzed cascade asymmetric desymmetrization reaction of cyclopentenediones with enals has been successfully initiated, followed with tandem aldol annulation, aromatization, as well as sequential methylation. The reactions proceeded well under mild reaction conditions, with broad substrate scope and good functional group tolerance, providing a rapid access to highly
Remarkable influence of secondary catalyst site on enantioselective desymmetrization of cyclopentenedione
作者:Madhu Sudan Manna、Santanu Mukherjee
DOI:10.1039/c3sc53102c
日期:——
An efficient, robust and highly enantioselective catalytic desymmetrization of 2,2-disubstituted cyclopentene-1,3-diones is developed via direct vinylogous nucleophilic addition of deconjugated butenolides.
The enantioselectivedesymmetrization via remote C(sp2)-H amidation of the prochiral 2,2-disubstituted cyclopentene-1,3-dione with N-methoxybenzamide has been developed. The overall process was catalyzed by a chiral bifunctional thiourea catalyst through a sequential conjugate-addition-elimination-tautomerization. This strategy provides rapid access to highly functionalized five-membered carbocycles
Silver-Catalyzed Asymmetric Desymmetrization of Cyclopentenediones via [3 + 2] Cycloaddition with α-Substituted Isocyanoacetates
作者:Jimil George、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.8b00590
日期:2018.4.20
A highly selective and practical asymmetric Ag(I) catalyst system has been developed for the [3 + 2] cycloaddition reactions between isocyanoacetates and cyclopentenediones. The current Ag(I) catalyst system tolerates moisture and air and readily utilizes class III solvents such as EtOAc and acetone. The development of on demand generation of an active chiral catalyst in the presence of isocyanides