Biomimetic Catalysis, Department of Chemistry , Technical University of Munich , Lichtenbergstrasse 4 , 85748 Garching , Germany.
Catalysis Research Center , Technical University of Munich , Ernst-Otto-Fischer-Straße 1 , 85748 Garching , Germany.
J Am Chem Soc. 2018 Mar 28;140(12):4344-4353. doi: 10.1021/jacs.8b00113. Epub 2018 Feb 19.
In contrast to Nature that accomplishes polyene cyclizations seemingly with ease, such transformations are difficult to conduct in the lab. In our program dealing with the development of selective halogenations of alkenes, we now asserted that standard X reagents are perfectly suited for the biomimetic cation-π cyclization of both electron rich and poor linear polyenes in the presence of the Lewis base morpholine and the Lewis acid HFIP. The method stands out due to its broad substrate scope and practicability together with high chemical yields and excellent selectivities, even for highly challenging chloriranium-induced polyene cyclizations.
与自然界似乎轻松完成多烯环化反应形成鲜明对比的是，此类转化在实验室中很难进行。在我们开展的烯烃选择性卤化反应开发项目中，我们现在断言标准 X 试剂非常适合在路易斯碱吗啉和路易斯酸 HFIP 的存在下，对富电子和缺电子的线性多烯进行仿生阳离子-π 环化反应。该方法具有广泛的底物范围和实用性，同时还具有高化学收率和优异的选择性，即使对于极具挑战性的氯鎓诱导多烯环化反应也是如此。
