Pd/Rh Dual Catalysis: Tandem Isomerization–Allylation to Access α-Quaternary Carbonyl Compounds

Abstract

A dual metal approach enables the use of unsymmetrical diallyl carbonates as viable enolate precursors for allylic alkylation reactions, allowing facile access to various α-quaternary allylated aldehydes and ketones. This methodology features a regioselective Pd-catalyzed decarboxylative oxidative addition, forming an electrophilic Pd π-allyl species and releasing an allylic alkoxide, which undergoes a Rh-catalyzed isomerization to an enolate in situ. Recombination of the Pd π-allyl species and Rhenolate nucleophile then affords the α-quaternary carbonyl compound.

Palladium-catalysed fragmentary esterification-induced allylic alkylation of allyl carbonates and cyclic vinylogous anhydrides

“…Avoiding the domination of autologous allyl etherification of allylic carbonates is essential for this protocol. 7 Increasing sp 3 character of the compound library is beneficial to the success of drug discovery. 8 In this context, we have developed a concise method for synthesizing structurally diverse CVAs and established a novel fragmentary esterification-induced allylic alkylation (FEAA), allowing for rapid access to highly functionalized 1,6-dicarbonyls with up to five stereocenters and excellent diastereoselectivity (Scheme 1c).…”