Controlling regioselectivity in deprotonative arylation of conjugated carbonyl systems remains a longstanding challenge. We report a Pd-catalyzed γ'-arylation of cyclic vinylogous esters (CVEs), enabled by Pd(dba)2/cataCXium A and hexamethylphosphoramide (HMPA) as a regioselectivity-governing additive. The method accommodates a broad range of (hetero)aryl bromides and CVE substrates. The resulting γ'-aryl CVEs were further converted to α-arylcycloalkenones via Stork-Danheiser transposition.
Li et al. (Thu,) studied this question.