title: Enantioselective copper-catalyzed alkynylation of benzopyranyl oxocarbenium ions.
abstract: We have developed highly enantioselective, copper-catalyzed alkynylations of benzopyranyl acetals. By using a copper(I) catalyst equipped with a chiral bis(oxazoline) ligand, high yields and enantioselectivities are achieved in the alkynylation of widely available, racemic isochroman and chromene acetals to deliver α-chiral oxygen heterocycles. This method demonstrates that chiral organometallic nucleophiles can be successfully used in enantioselective additions to oxocarbenium ions.
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Harathi D
authors.initials: HD
authors.lastname: Srinivas
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Prantik
authors.initials: P
authors.lastname: Maity
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Glenn P A
authors.initials: GP
authors.lastname: Yap
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Watson
mesh_terms: D001578:Benzopyrans / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D015394:Molecular Structure; D009861:Onium Compounds / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010080:Oxazoles / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001578:Benzopyrans; D009861:Onium Compounds; D009942:Organometallic Compounds; D010080:Oxazoles; D003300:Copper
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