Catalytic Asymmetric γ-Alkylation of Carbonyl Compounds via Stereoconvergent Suzuki Cross-Couplings
摘要:
With the aid of a chiral nickel catalyst, enantioselective gamma- (and delta-) alkylations of carbonyl compounds can be achieved through the coupling of gamma-haloamides with alkylboranes. In addition to primary alkyl nucleophiles, for the first time for an asymmetric cross-coupling of an unactivated alkyl electrophile, an arylmetal, a boronate ester, and a secondary (cyclopropyl) alkylmetal compound are shown to couple with significant enantioselectivity. A mechanistic study indicates that cleavage of the carbon-halogen bond of the electrophile is irreversible under the conditions for asymmetric carbon-carbon bond formation.
Catalytic Asymmetric γ-Alkylation of Carbonyl Compounds via Stereoconvergent Suzuki Cross-Couplings
摘要:
With the aid of a chiral nickel catalyst, enantioselective gamma- (and delta-) alkylations of carbonyl compounds can be achieved through the coupling of gamma-haloamides with alkylboranes. In addition to primary alkyl nucleophiles, for the first time for an asymmetric cross-coupling of an unactivated alkyl electrophile, an arylmetal, a boronate ester, and a secondary (cyclopropyl) alkylmetal compound are shown to couple with significant enantioselectivity. A mechanistic study indicates that cleavage of the carbon-halogen bond of the electrophile is irreversible under the conditions for asymmetric carbon-carbon bond formation.
Catalytic Asymmetric γ-Alkylation of Carbonyl Compounds via Stereoconvergent Suzuki Cross-Couplings
作者:Susan L. Zultanski、Gregory C. Fu
DOI:10.1021/ja2079515
日期:2011.10.5
With the aid of a chiral nickel catalyst, enantioselective gamma- (and delta-) alkylations of carbonyl compounds can be achieved through the coupling of gamma-haloamides with alkylboranes. In addition to primary alkyl nucleophiles, for the first time for an asymmetric cross-coupling of an unactivated alkyl electrophile, an arylmetal, a boronate ester, and a secondary (cyclopropyl) alkylmetal compound are shown to couple with significant enantioselectivity. A mechanistic study indicates that cleavage of the carbon-halogen bond of the electrophile is irreversible under the conditions for asymmetric carbon-carbon bond formation.