Development of a Method for the Reductive Cyclization of Enones by a Titanium Catalyst
作者:Natasha M. Kablaoui、Stephen L. Buchwald
DOI:10.1021/ja954192n
日期:1996.1.1
which bis(trimethylphosphine)titanocene is used to catalyze the reductive cyclization of enones to cyclopentanols via a metallacyclic intermediate has been developed. The key step in the process is the cleavage of the titanium−oxygen bond in the metallacycle by a silane to regenerate the catalyst. Mechanistic aspects of the reaction are discussed and the diastereoselectivity of the transformation is studied
已经开发了一种有效的方案,其中双(三甲基膦)二茂钛用于通过金属环中间体催化烯酮还原环化为环戊醇。该过程的关键步骤是通过硅烷裂解金属环中的钛-氧键以再生催化剂。讨论了反应的机理方面,并使用非手性和手性底物研究了转化的非对映选择性。描述了该过程的范围和限制。还开发了用于生成空气和湿度敏感催化剂的原位协议。这项工作首次证明了使用早期过渡金属配合物催化烯烃与含杂原子官能团的还原环化的可行性。