Zinc Catalyzed and Mediated Asymmetric Propargylation of Trifluoromethyl Ketones with a Propargyl Boronate
作者:Daniel R. Fandrick、Jonathan T. Reeves、Johanna M. Bakonyi、Prasanth R. Nyalapatla、Zhulin Tan、Oliver Niemeier、Deniz Akalay、Keith R. Fandrick、Wolfgang Wohlleben、Swetlana Ollenberger、Jinhua J. Song、Xiufeng Sun、Bo Qu、Nizar Haddad、Sanjit Sanyal、Sherry Shen、Shengli Ma、Denis Byrne、Ashish Chitroda、Victor Fuchs、Bikshandarkoil A. Narayanan、Nelu Grinberg、Heewon Lee、Nathan Yee、Michael Brenner、Chris H. Senanayake
DOI:10.1021/jo400080y
日期:2013.4.19
modeling at the density functional level of theory. A water acceleration effect on the zinc-catalyzed propargylation was discovered, which enabled a catalytic process to be achieved. Reaction progress analysis supports a predominately rate limiting exchange for the zinc-catalyzed propargylation. A catalytic amount of water is proposed to generate an intermediate that catalyzes the exchange, thereby facilitating
提出了锌介导的和催化的三氟甲基酮与炔丙基硼烷和N-异丙基-1-脯氨酸配体的不对称炔丙基化的发展。该方法提供了中度到高度的立体选择性,并成功应用于多千克规模的糖皮质激素激动剂BI 653048的合成。提出了与炔丙基硼烷交换硼-锌的机理,并在理论的密度泛函水平上进行了建模。发现水促进了锌催化的炔丙基化反应,从而实现了催化过程。反应进度分析主要支持限速交换,以促进锌催化的炔丙基化。提出了催化量的水以产生催化交换的中间体,从而促进与三氟甲基酮的反应。