<i>N</i>-Heterocyclic Carbene-Initiated α-Acylvinyl Anion Reactivity: Additions of α-Hydroxypropargylsilanes to Aldehydes

Highly substituted α,β-unsaturated ketones are prepared by the N-heterocyclic carbene-initiated addition of α-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 β-position of the product (R1) can be accommodated in moderate to excellent yields with a high degree of control over the resulting alkene.