Highly Effective Vinylogous Mukaiyama−Michael Reaction Catalyzed by Silyl Methide Species Generated from 1,1,3,3-Tetrakis(trifluoromethanesulfonyl)propane

Silyl methide species in situ generated from 1,1,3,3-tetrakis(trifluoromethanesulfonyl)propane (Tf2CHCH2CHTf2) performed as an excellent acid catalyst for the vinylogous Mukaiyama−Michael reaction of α,β-unsaturated ketones with 2-silyloxyfurans. Notably, the required loading of Tf2CHCH2CHTf2 to obtain the 1,4-adducts in reasonable yield was significantly low (from 0.05 to 1.0 mol %). This carbon acid-mediated VMM reaction provides a powerful synthetic methodology to construct highly substituted γ-butenolide structure.