Pd-Catalyzed Regio-, Diastereo-, and Enantioselective Construction of Vicinal Tertiary Stereocenters from Cyclic Allylboronate Salts and Allyl Electrophiles

Abstract

A regio-, diastereo-, and enantioselective Pd-catalyzed allylation of the lithium salts of 6-membered cyclic allylboronates is reported. The system relies on the use of a commercially available C₂-symmetric chiral bisphosphine ligand and gives access to borylated 1,5-dienes featuring vicinal 3,4-cis tertiary stereocenters. It delivers uniformly high enantiocontrol across the series, together with high regio- and diastereoselectivity for the majority of substrates. Furthermore, the method simplifies the synthesis of stereochemically complex tetrahydrofuran derivatives possessing three contiguous stereocenters after the standard oxidation and acidic treatment of the borylated products.