title: Single-Step Modular Synthesis of Unsaturated Morpholine N-Oxides and Their Cycloaddition Reactions.
abstract: A single-flask procedure for the generation of α-keto-N-alkenylnitrones through a Chan-Lam coupling and subsequent spontaneous 6π electrocyclization of these intermediates for the synthesis of 2H-1,4-oxazine N-oxides has been developed for a variety of α-ketooximes and alkenylboronic acids. This transformation provides a new approach to C-substituted unsaturated morpholine derivatives that are poised to undergo further functionalization for the preparation of a diverse array of novel heterocyclic structures. The scope of the new method for the synthesis of 2H-1,4-oxazine N-oxides is discussed, in addition to initial studies describing the cycloaddition reactivity of these new heterocyclic intermediates.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, USA.
authors.forename: Jongwoo
authors.initials: J
authors.lastname: Son
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, USA.
authors.forename: Ki Hwan
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, USA.
authors.forename: Dong-Liang
authors.initials: DL
authors.lastname: Mo
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, USA.
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Wink
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 W. Taylor St., Chicago, IL, USA.
authors.forename: Laura L
authors.identifier: 0000-0002-8764-7522
authors.initials: LL
authors.lastname: Anderson
keywords: Chan-Lam coupling; electrocyclization; morpholines; nitrones; oxazine N-oxides