Department of Chemistry, The Scripps Research Institute , 130 Scripps Way, Jupiter, Florida 33458, United States.
Department of Chemistry, University of Chicago , 5735 South Ellis Avenue, Chicago, Illinois 60637, United States.
J Am Chem Soc. 2017 May 10;139(18):6329-6337. doi: 10.1021/jacs.6b12653. Epub 2017 May 2.
Although the addition of acid halides across olefins is well-studied, limitations remain with a number of substrate classes that possess leaving groups, polyunsaturation, and acid-sensitive moieties, particularly polyenes prone to cyclization. The process is also challenging when conducted on a small scale, and moreover, methods for the addition of their deuterated counterparts typically require special techniques, especially when control of stoichiometry is required. Herein is described a readily synthesized and handled reagent class which can accomplish the controlled and selective Markovnikov addition of both HCl and HBr across several alkene classes under mild reaction conditions tolerant of diverse functionality. The process is particularly valuable on a laboratory scale, and direct comparisons to other methods are provided. As a result of in-depth mechanistic studies seeking to understand how these novel tools work and the active species behind their efficacy, the means to easily add DCl and DBr using a controlled amount of DO was discovered along with the critical role of hydrolysis in leading to active hydrohalogenation species.
尽管烯烃的卤化酸加成反应已经得到了很好的研究，但仍存在一些限制，这些限制存在于许多具有离去基团、多不饱和性和酸敏性基团的底物类别中，特别是容易发生环化的多烯烃。当在小规模下进行时，该过程也具有挑战性，而且，氘代对应物的加成方法通常需要特殊的技术，特别是当需要控制化学计量时。本文描述了一类易于合成和处理的试剂，它可以在温和的反应条件下，控制并选择性地完成 HCl 和 HBr 在几种烯烃类中的 Markovnikov 加成反应，这些条件对多种官能团具有耐受性。该过程在实验室规模上特别有价值，并提供了与其他方法的直接比较。通过深入的机理研究，我们试图了解这些新工具的工作原理以及它们有效性背后的活性物质，发现了使用可控量的 DO 轻松添加 DCl 和 DBr 的方法，以及水解在产生活性卤化氢物种中的关键作用。
