title: Asymmetric propargylation of ketones using allenylboronates catalyzed by chiral biphenols.
abstract: Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3'-Br(2)-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60-98%) and high enantiomeric ratios (3:1-99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr >86:14) and enantioselectivities (er >92:8) under the catalytic conditions.
authors: Department of Chemistry, Life Science and Engineering Building, Boston University, 24 Cummington Street, Boston, Massachusetts 02215, USA.
authors: David S
authors: DS
authors: Barnett
authors: Scott E
authors: SE
authors: Schaus
mesh_terms: D000466:Alkadienes / Q000737:chemistry*; D001888:Boric Acids / Q000737:chemistry*; D002384:Catalysis; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry; D010636:Phenols / Q000737:chemistry*; D011407:Propane / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000466:Alkadienes; C406944:BINOL, naphthol; D001888:Boric Acids; D007659:Ketones; D009284:Naphthols; D010636:Phenols; C025947:propadiene; C032688:boric acid; D011407:Propane