We report an N-heterocyclic carbene(NHC)-catalyzed[10π+2π]cycloaddition between indene-2-carbaldehydes and isatins,delivering spirooxindole-γ-butyrolactones with moderate yields(up to 68%)and excellent enantioselec...We report an N-heterocyclic carbene(NHC)-catalyzed[10π+2π]cycloaddition between indene-2-carbaldehydes and isatins,delivering spirooxindole-γ-butyrolactones with moderate yields(up to 68%)and excellent enantioselectivity(up to 93%ee).This transformation proceeds via NHC-bound isobenzofulvene intermediates and represents the first successful application of all-carbon higherene in NHC-catalyzed[10π+2π]cycloadditions.展开更多
The[8+4]cycloaddition of indene-2-carbaldehydes with indole-2,3-quinodimethanes and pyrrolidone-3,4-dienes is described,affording indole and pyrrolidone annulated bicyclo[4.2.1]nonanes in a highly peri-,diastereo-,and...The[8+4]cycloaddition of indene-2-carbaldehydes with indole-2,3-quinodimethanes and pyrrolidone-3,4-dienes is described,affording indole and pyrrolidone annulated bicyclo[4.2.1]nonanes in a highly peri-,diastereo-,and enantioselective fashion in the presence of a secondary amine catalyst.This reaction,which proceeds through catalytically generated isobenzofulvenes,represents the first asymmetric version of high-order[8+4]cycloaddition.展开更多
基金support from the Key Project of Zhejiang Provincial Natural Science Foundation(LZ23B020003)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2022R01007)the Start-up Research Grant from Zhejiang Normal University.
文摘We report an N-heterocyclic carbene(NHC)-catalyzed[10π+2π]cycloaddition between indene-2-carbaldehydes and isatins,delivering spirooxindole-γ-butyrolactones with moderate yields(up to 68%)and excellent enantioselectivity(up to 93%ee).This transformation proceeds via NHC-bound isobenzofulvene intermediates and represents the first successful application of all-carbon higherene in NHC-catalyzed[10π+2π]cycloadditions.
基金This work is supported by the National Natural Science Foundation of China(Nos.21772038 and 21971062)The authors thank the Research Center of Analysis and Test of East China University of Science and Technology for the assistance with the HRMS and NMR analysis.
文摘The[8+4]cycloaddition of indene-2-carbaldehydes with indole-2,3-quinodimethanes and pyrrolidone-3,4-dienes is described,affording indole and pyrrolidone annulated bicyclo[4.2.1]nonanes in a highly peri-,diastereo-,and enantioselective fashion in the presence of a secondary amine catalyst.This reaction,which proceeds through catalytically generated isobenzofulvenes,represents the first asymmetric version of high-order[8+4]cycloaddition.
