1,6-Nucleophilic Di- and Trifluoromethylation of para -Quinone Methides with Me 3 SiCF 2 H/Me 3 SiCF 3 Facilitated by CsF/18-Crown-6.

The direct 1,6-nucleophilic difluoromethylation, trifluoromethylation, and difluoroalkylation of para -quinone methides ( p -QMs) with Me 3 SiRf (Rf = CF 2 H, CF 3 , CF 2 CF 3 , CF 2 COOEt, and CF 2 SPh) under mild conditions are described. Although Me 3 SiCF 2 H shows lower reactivity than Me 3 SiCF 3 , it can react with p -QMs promoted by CsF/18-Crown-6 to give structurally diverse difluoromethyl products in good yields. The products can then be further converted into fluoroalkylated para -quinone methides and α -fluoroalkylated diarylmethanes.