title: Enantioselective Copper(I)-Catalyzed Alkynylation of Oxocarbenium Ions to Set Diaryl Tetrasubstituted Stereocenters.
abstract: An enantioselective, copper(I)-catalyzed addition of terminal alkynes to isochroman ketals to set diaryl, tetrasubstituted stereocenters has been developed. The success of this reaction relies on identification of a Cu/PyBox catalyst capable of distinguishing the faces of the diaryl-substituted oxocarbenium ion. This challenging transformation enables efficient conversion of readily available, racemic ketals into high-value enantioenriched isochroman products with fully substituted stereogenic centers. High yields and enantiomeric excesses are observed for various isochroman ketals and an array of alkynes.
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (USA).
authors.forename: Srimoyee
authors.initials: S
authors.lastname: Dasgupta
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (USA).
authors.forename: Thomas
authors.initials: T
authors.lastname: Rivas
authors.affiliation: Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716 (USA). mpwatson@udel.edu.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Watson
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D002867:Chromones / Q000138:chemical synthesis* / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008968:Molecular Conformation; D009861:Onium Compounds / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000480:Alkynes; D002867:Chromones; D007477:Ions; D009861:Onium Compounds; D009942:Organometallic Compounds; D003300:Copper
keywords: alkynes; asymmetric catalysis; enantioselectivity; oxocarbenium ion; oxygen heterocycles