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Asymmetric Synthesis of Oxa‐Bridged Oxazocines through a Catalytic Rh II /Zn II Relay [4+3] Cycloaddition Reaction
Author(s) -
Xu Chaoran,
Wang Kaixuan,
Li Dawei,
Lin Lili,
Feng Xiaoming
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201910898
Subject(s) - cycloaddition , chemistry , catalysis , stereoselectivity , bimetallic strip , rhodium , hydroformylation , ligand (biochemistry) , medicinal chemistry , transition metal , stereochemistry , organic chemistry , biochemistry , receptor
Oxa‐bridged oxazocines bearing three chiral carbon centers were synthesized efficiently through a bimetallic catalytic asymmetric tandem reaction of β,γ‐unsaturated α‐ketoesters with diazoimides. The process contained a rhodium‐promoted in situ generation of isomünchnone from diazoimide decomposition, and a [4+3]‐cycloaddition of β,γ‐unsaturated α‐ketoester catalyzed by a chiral N , N′ ‐dioxide‐Zn II complex. Ligand‐accelerated catalysis was found, and a possible transition‐state model was proposed to explain the origin of stereoselectivity.