Development of new catalytic enantioselective formation of methylenelactam-based N,O-spirocyclic compounds via ring opening-asymmetric reclosure of hydroxylactams

Catalytic enantioselective formation of methylenelactam-based N,O-spirocyclic compounds is developed. Hydroxylactams prepared from N-carbonyl phthalimides and beta-amido functionalized allylboronates underwent ring opening-asymmetric reclosure in the presence of catalytic amounts of MgBr2 and a chiral aminophenol to afford the corresponding N,O-spirocyclic compounds in excellent yields and high enantioselectivities. (C) 2020 Elsevier Ltd. All rights reserved.