Catalytic asymmetric α-aldol reaction of vinylogous N-heterocyclic carbene enolates: formation of quaternary and labile tertiary stereocenters.
Simple N-heterocyclic carbene (NHC)-enolates are widely studied versatile species. However, their vinylogous siblings (i.e., vinylogous NHC-enolates) have been much less studied. Here we disclose the first catalytic asymmetric α-aldol reaction of vinylogous NHC-enolates. With trifluoropyruvate as the carbon electrophile, the efficient C-C bond formation process displays not only complete α-regioselectivity but also excellent stereocontrol over the two newly established challenging stereocenters (one quaternary and the other labile tertiary), furnishing a range of highly enantioenriched β,γ-unsaturated α-fluoroalkylated esters.
Department of Chemistry, The Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China.
Xiuqin
X
Dong
Jianwei
J
Sun