bromides. The reaction proceeds efficiently when a combination of a highly substituted bromoalkene and a hydrazone derived from a ketone are employed, pointing to the convenience of a stericallyencumbered environment. This unprecedented process allows for the stereocontrolled preparation of highly substituted dienes and polyenes.
Synthesis of 1,1-Disubstituted Olefins via Catalytic Alkyne Hydrothiolation/Kumada Cross-Coupling
作者:Anthony Sabarre、Jennifer Love
DOI:10.1021/ol8012843
日期:2008.9.18
Using recently developed methodology for the regioselective formation of branched alkyl vinyl sulfides, we report a convenient route to 1,1-disubstituted olefins. We demonstrate that n-propanethiol successfully undergoes catalytic alkyne hydrothiolation with both aryl and aliphatic alkynes using Tp*Rh(PPh3)2 as the catalyst. The resulting vinyl sulfides undergo Kumada cross-coupling to afford the desired
styrene and vinylarenes, the aryl and vinyl groups routinely insert at the β position. However, selective insertion at the αposition has been very rare. Herein, we provide a missing piece in the palette of Heck reaction, which gave >20:1 αselectivity. The key to our success is a new ferrocene 1,1′‐bisphosphane (dnpf) that carries 1‐naphthyl groups. Our mechanistic studies revealed that the high α selectivity
Site‐selective Hydrogenation/Deuteration of Benzylic Olefins Enabled by Electroreduction Using Water
作者:Simon Kolb、Daniel B. Werz
DOI:10.1002/chem.202300849
日期:——
Electroreduction of benzylicolefins has been applied to site-selectively hydrogenate such double bonds while other functions that react under regular hydrogenation conditions are present. By the use of water as proton source this protocol also allows deuteration by simply switching to D2O. The applicability of this method was shown by the use of a commercially available electrolysis setup and a broad
苄基烯烃的电还原已应用于位点选择性氢化此类双键,同时存在在常规氢化条件下反应的其他功能。通过使用水作为质子源,该协议还允许通过简单地切换到 D 2 O 进行氘化。该方法的适用性通过使用商用电解装置和广泛的底物范围得到证明。
Intermolecular Coupling Reaction of Alkynes with Vinyl Bromide with Selective Skeletal Rearrangement