Synthesis of masked α,β-unsaturated trifluoromethyl ketones via iodine(III)-mediated double decarboxylative trifluoroacetylation.

An iodine(III)-mediated double decarboxylative trifluoroacetylation of masked α,β-unsaturated carboxylic acids with cyclic CF3-pyruvate acetals is reported. This metal-free protocol employs PhI(OCOMe)2 as a dual-function decarboxylative reagent to forge C-C bonds via a radical pathway, delivering a diverse array of masked α,β-unsaturated trifluoromethyl ketones under simple thermal conditions with broad functional group tolerance. Gram-scale synthesis and downstream transformations highlight the synthetic utility, while mechanistic studies implicate sequential single-electron transfer and decarboxylation events.