Department of Chemistry, University of Washington , Seattle, Washington 98195, United States.
J Am Chem Soc. 2017 May 24;139(20):6969-6977. doi: 10.1021/jacs.7b02104. Epub 2017 May 12.
We have developed catalytic anti-Markovnikov hydroallylation of terminal and functionalized internal alkynes. In this article, we describe the development of the reaction, exploration of the substrate scope, and a study of the reaction mechanism. Synthesis of skipped dienes through the hydroallylation of terminal alkyl and aryl alkynes with simple allyl phosphates and 2-substituted allyl phosphates is described. The hydroallylation of functionalized internal alkynes leads to the formation of skipped dienes containing trisubstituted alkenes. We demonstrate that the hydroallylation of internal alkynes can be used in the regio- and diastereoselective synthesis of complex trisubstituted alkenes. A mechanism of the hydroallylation reaction is proposed, and experimental evidence is provided for the key steps of the catalytic cycle. Stoichiometric experiments demonstrate an unexpected role of lithium alkoxide in the carbon-carbon bond-forming step of the reaction. A study of the hydrocupration of internal alkynes provides new insight into the structure, stability, and reactivity of alkenyl copper intermediates, as well as insight into the source of the regioselectivity in reactions of internal alkynes.
我们开发了末端和官能化内部炔烃的催化反马氏加成的水合反应。在本文中，我们描述了反应的发展、底物范围的探索以及反应机理的研究。通过简单的烯丙基膦酸盐和 2-取代的烯丙基膦酸盐与末端烷基和芳基炔烃的水合加成反应，合成了缺失二烯。官能化内部炔烃的水合加成反应导致含有三取代烯烃的缺失二烯的形成。我们证明了内部炔烃的水合加成反应可用于复杂三取代烯烃的区域和立体选择性合成。提出了水合加成反应的机理，并提供了催化循环关键步骤的实验证据。化学计量实验证明了锂醇盐在反应的碳-碳键形成步骤中具有意想不到的作用。对内部炔烃的水合铜化反应的研究提供了对烯基铜中间体的结构、稳定性和反应性的新认识，以及对内部炔烃反应区域选择性来源的认识。
