Β‐Lactams as Formal Dipoles through Amide‐Bond Activation. Issue 3 (9th December 2015)

• Record Type: Journal Article
• Authors: Barbier, Vincent; Marrot, Jérôme; Couty, François; David, Olivier R. P.
• Is Part Of: European journal of organic chemistry. Issue 3(2016)
• Page Start: 549
• Page End: 555
• Publication Date: 2015-12-09
• Subjects: Organocatalysis -- Lewis bases -- Lactams -- Nitrogen heterocycles -- Ring expansion; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201501342
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: Activation of β‐lactams can be achieved by simple Lewis‐base catalysis to trigger an unprecedented reaction based on the formal dipolar behaviour of a strained amide bond. A new synthetic route for 1, 3‐oxazinan‐6‐ones is presented by reaction of β‐lactams with ethylglyoxylate, which after methodological optimizations identified 4‐pyrrolidinopyridine as the catalyst of choice in aprotic polar solvents. Mechanistic details are also discussed in light of the intrinsic limitations identified for this transformation. Abstract : The C–N bond of an activated lactam can be seen as a formal dipole able to react with a very electrophilic aldehyde under Lewis‐base catalysis. Substituted oxazinanone heterocycles can be prepared in good yields. Mechanistic details were explored and limitations of this transformation were rationalized.