Copper-catalyzed enantioselective 1,4-addition of alkyl groups to N-sulfonyl imines

Chem Commun (Camb). 2014 Dec 28;50(100):15897-900. doi: 10.1039/c4cc07134d.

Abstract

In copper(I)/phosphoramidite-catalyzed asymmetric 1,4-additions of dialkylzinc, N-sulfonyl imines are more reactive and furnish higher enantiomeric excesses than the respective cycloalk-2-enones. This enables formation of a quaternary stereocenter as well as a cis-selective addition to an imine derived from 5-methylcyclohex-2-enone. The 1,4-adducts can be transformed in stereodivergent reductions yielding cis- or trans-3-alkylcycloalkyl amides.