Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O–H and N–H Additions
作者:Jeff P. Costello、Eric M. Ferreira
DOI:10.1021/acs.orglett.9b03557
日期:2019.12.20
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization
阐明了铂催化的分子内加氢烷氧基化中区域选择性的空间和电子驱动因素。发现了一个分支点,该分支点将过程分为 5-exo 和 6-endo 选择性过程,并且对于两种氧杂环都可以以良好的产率获得烯醇醚。主要影响来自电子效应,其中炔烃取代基诱导炔烃极化,从而导致杂原子优先攻击更缺电子的碳。在其他情况下研究电子效应,包括加氢酰氧基化和加氢胺化,尽管没有统一观察到,但方向性的类似趋势占主导地位。