Copper(i) catalyzed asymmetric 1,2-addition of Grignard reagents to -methyl substituted ,-unsaturated ketonesThis article is part of the ChemComm Emerging Investigators 2012 themed issue.Electronic supplementary information (ESI) available. See DOI: 10.1039/c1cc16725a

The first catalytic enantioselective 1,2-addition of Grignard reagents to ketones is presented. This additive-free copper( i ) catalyzed 1,2-addition provides chiral allylic tertiary alcohols with an er of up to 98:2 and excellent yields due to the complete shift of overwhelming 1,4-selectivity of copper( i )-catalysts towards 1,2-selectivity in the addition reaction to enones. Copper-catalyzed 1,2-addition of Grignard reagents to enones has been achieved for the first time with high enantioselectivities and excellent yields.