Diastereoselective Base-Catalyzed Formal [4 + 2] Cycloadditions of N‑Sulfonyl Imines and Cyclic Anhydrides
journal contributionposted on 04.05.2017, 21:04 by Stephen W. Laws, Lucas C. Moore, Michael J. Di Maso, Q. Nhu N. Nguyen, Dean J. Tantillo, Jared T. Shaw
A diastereoselective base-catalyzed Mannich reaction of cyclic, enolizable anhydrides and N-sulfonyl imines for the synthesis of δ-lactams is reported. This anhydride Mannich reaction tolerates imines derived from aryl and enolizable aldehydes. A base-catalyzed product epimerization pathway ensures high anti diastereoselectivity in aryl and achiral enolizable imines.