Molecules (Jun 2024)
1,6-Nucleophilic Di- and Trifluoromethylation of <i>para</i>-Quinone Methides with Me<sub>3</sub>SiCF<sub>2</sub>H/Me<sub>3</sub>SiCF<sub>3</sub> Facilitated by CsF/18-Crown-6
Abstract
The direct 1,6-nucleophilic difluoromethylation, trifluoromethylation, and difluoroalkylation of para-quinone methides (p-QMs) with Me3SiRf (Rf = CF2H, CF3, CF2CF3, CF2COOEt, and CF2SPh) under mild conditions are described. Although Me3SiCF2H shows lower reactivity than Me3SiCF3, 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.
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