N-heterocyclic carbene-initiated alpha-acylvinyl anion reactivity: additions of alpha-hydroxypropargylsilanes to aldehydes.

Highly substituted alpha,beta-unsaturated ketones are prepared by the N-heterocyclic carbene-initiated addition of alpha-hydroxypropargylsilanes to aldehydes. This strategy serves as a highly efficient alternative to the standard Morita-Baylis-Hillman (MBH) approaches for these types of compounds. In contrast to the MBH reaction, different substitution in the beta-position of the product (R1) can be accommodated in moderate to excellent yields with a high degree of control over the resulting alkene.