Addition/elimination reactions of ethylsulfonyl pyridines: stereoselective synthesis of vinylpyridine allylic alcohols
作者:Gregory W. O’Neil、Nathan D. Drake、Jennifer M. Storvick
DOI:10.1016/j.tetlet.2012.12.049
日期:2013.2
2-(Phenylsulfonyl)ethyl pyridines can be coupled with aldehydes leading directly to sulfone-eliminated vinylpyridine allylic alcohols. These products are obtained in good yield and with high levels of stereocontrol.
An Fe-catalyzed unprotected hydroxylamine mediated Heck-type coupling between sulfinic acids and alkenes for the regioselective synthesis of (E)-vinyl sulfones has been developed. Mechanism studies indicated for the first time that a radical process may be involved and that hydroxylamines play multiple roles, including those of a mild oxidant and an in situ base. It was found for the first time that
已经开发了 Fe 催化的未保护羟胺介导的亚磺酸和烯烃之间的 Heck 型偶联,用于 ( E )-乙烯基砜的区域选择性合成。机理研究首次表明可能涉及自由基过程,并且羟胺发挥多种作用,包括温和氧化剂和原位碱。首次发现这种转化不仅实现了未保护的羟胺促进C-S键的构建,而且为结构重要的( E )-乙烯基砜的制备提供了一种实用且互补的方法。
Ni-Catalyzed Hydrosulfonylation of Alkenes with Aromatic Iodides and K<sub>2</sub>S<sub>2</sub>O<sub>5</sub>
as the final reductant enables the efficient formation of aryl and heteroaryl sulfinate intermediates, which undergo Michael-type additions to electron-deficient alkenes for initiating the hydrosulfonylation process. Moreover, the superiority of this protocol is demonstrated by broad substrate scope and good functional group compatibility.
提出了通过 SO 2插入策略用容易获得的芳香族碘化物进行烯烃的氢磺酰化。非贵金属 Ni 催化与 ( i Pr) 3 SiH 作为最终还原剂的组合能够有效形成芳基和杂芳基亚磺酸盐中间体,这些中间体与缺电子烯烃进行迈克尔型加成以引发氢磺酰化过程。此外,该协议的优越性通过广泛的底物范围和良好的官能团兼容性得到证明。
Visible‐Light‐Promoted Catalyst‐Free Oxyarylation and Hydroarylation of Alkenes with Carbon Dioxide Radical Anion
作者:Jing Hou、Li‐Li Hua、Yan Huang、Le‐Wu Zhan、Bin‐Dong Li
DOI:10.1002/asia.202201092
日期:2023.1.3
Visible-light-mediated oxyarylation and hydroarylation of alkenes with aryl halides using formate salts as the reductant and hydrogen source under ambient conditions were developed. The protocol represents a rare catalyst-free example of the realization of such transformations.