An enantioselective 1,4-conjugate addition of nitromethane to β-silyl α,β-unsaturated carbonyl compounds catalyzed by bifunctional squaramide catalysts has been developed. This methodology offers both enantiomers of β-silyl nitroalkanes in good to excellent yields (up to 92%) and enantioselectivities (up to 97.5% ee) under solvent-free conditions at room temperature. Control experiments reveal that the presence of a β-silyl group in the enones is crucial for high reactivity under the optimized reaction conditions.
Keywords: chiral organosilanes; organocatalysis; solvent-free synthesis; β-silyl nitroalkanes; β-silyl α,β-unsaturated carbonyl compounds.
Copyright © 2021, Dubey and Chowdhury.