Asymmetric Propargylation of Ketones Using Allenylboronates Catalyzed by Chiral Biphenols
作者:David S. Barnett、Scott E. Schaus
DOI:10.1021/ol201535b
日期:2011.8.5
Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3′-Br2-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)
手性双酚使用丙二烯基硼酸酯催化酮的对映选择性不对称炔丙基化。该反应使用 10 mol% 的 3,3'-Br 2 -BINOL 作为催化剂,烯丙基二氧硼烷作为亲核试剂,在没有溶剂的情况下,在微波辐射下得到高炔丙醇。以良好的产率 (60–98%) 和高对映体比率 (3:1–99:1) 获得反应产物。使用手性外消旋丙二烯基硼酸酯的非对映选择性炔丙基化在催化条件下产生良好的非对映选择性 (dr >86:14) 和对映选择性 (er >92:8)。