Stereoselective Allylic Alkylation with Azlactones Using Triphenylarsine

Significance

Allylic alkylation remains an important method for accessing important synthetic intermediates. The authors utilize chiral starting allylic esters and alkylated them with azlactones. Interestingly, the diastereoselectivity was reversed when they switched from bidentate ligands to monodentate ligands. Toluene and NaHMDS was determined to be the best solvent/base system with the bidentate ligands whereas THF and LiHMDS was used with the monodentate ligands. Importantly, this method provides contiguous quaternary-tertiary chiral carbon centers stereoselectively.