Development of Chemo- and Enantioselective Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation of alpha-Nitroesters

摘要

We describe the development of a Pd-catalyzed decarboxylative asymmetric allylic alkylation of alpha-nitro allyl esters to afford acyclic tetrasubstituted nitroalkanes. Optimization of the reaction parameters revealed unique ligand and solvent combinations crucial for achieving chemo- and enantioselective C-alkylation of electronically challenging benzylic nitronates and sterically encumbered 2-allyl esters. Substrates were efficiently accessed in a combinatorial fashion by a cross-Claisen/ alpha-arylation sequence. The method provides functional group orthogonality that complements nucleophilic imine allylation strategies for alpha-tertiary amine synthesis.