N-heterocyclic carbene catalyzed additions of 3-trimethylsilyl propiolate to aldehydes

A N-heterocyclic carbene (NHC) catalyzed addition reaction of 3-trimethylsilyl propiolate with aldehydes has been developed. Under the catalysis of 2mol% NHCs, benzaldehyde, furfural, β-naphthaldehyde, meta- and para-substituted aromatic aldehydes reacted with 3-trimethylsilyl propiolate to afford β-acylated MBH adducts in good yield with excellent stereoselectivity. While ortho-substituted benzaldehydes coupled with 3-trimethylsilyl propiolate to give alkynylation products as the sole products under the same reaction conditions.