Enantioselective copper-catalyzed cascade inter- and intramolecular amidation was achieved between ethynyl benzoxazinanones and α-halohydroxamates in the presence of an indapybox ligand. The one-pot cascade transformation was triggered by the attack of hydroxamates to dipolar copper-allenylidene intermediates, followed by a nucleophilic annulation reaction. Thus, a series of -methylene 3-aminoindoline derivatives were obtained in good yields with high enantioselectivities under mild reaction conditions.
View Article and Find Full Text PDFAn asymmetric [3 + 2] cycloaddition of vinyl ethylenecarbonates (VECs) and ()-3-arylvinyl substituted benzo[] isothiazole 1,1-dioxides has been developed using the Pd complex of a bidentate phosphoramidite (Me-BIPAM) as the catalyst, providing a wide variety of chiral multistereogenic vinyltetrahydrofurans in good yields with excellent diastereo- and enantioselectivities (up to >20:1 , 99% ).
View Article and Find Full Text PDFThe combination of chiral binaphthyl box-copper(II) with triflimide (TfNH) was identified as an efficient catalytic system for the asymmetric Michael/ketalization of ()-2-hydroxyaryl-2-oxobut-3-enoates or ()-ethyl 4-(2-aminoaryl)-2-oxobut-3-enoates with pyrazolone derivatives. The corresponding asymmetric tandem reactions provided a series of enantioenriched aryl and heteroaryl fused 2,8-,- or ,-bicyclo[3.3.
View Article and Find Full Text PDFA 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 functionalized chiral 2,2-disubstituted 1,3-indandione derivatives containing an all-carbon quaternary stereogenic center in moderate to good yields with high enantioselectivities.
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