title: Diastereoselective 1,3-dipolar cycloaddition of nitrones to donor-acceptor cyclopropanes catalyzed by a calcium(II) complex.
abstract: Calcium triflate has been identified as an efficient catalyst for the cycloaddition of nitrones to donor-acceptor cyclopropanes. The reaction proceeds with good to excellent yields of the corresponding tetrahydro-1,2-oxazines with high levels of diastereoselectivity. The generality of the reaction allowed for the synthesis of tetrahydro-1,2-oxazines bearing alkyl, aryl, and heteroaromatic substitution.
authors.affiliation: University of Richmond , 28 Westhampton Way, Richmond, Virginia 23173, United States.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Braun
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Congdon
authors.forename: Kristine A
authors.initials: KA
authors.lastname: Nolin
mesh_terms: D002118:Calcium / Q000737:chemistry*; D002384:Catalysis; D061565:Cycloaddition Reaction; D003521:Cyclopropanes / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D010078:Oxazines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003521:Cyclopropanes; D009589:Nitrogen Oxides; D010078:Oxazines; C015388:nitrones; D002118:Calcium