Stereo- and Enantioselective Benzylic C–H Alkenylation via Photoredox/Nickel Dual Catalysis
作者:Xiaokai Cheng、Tongtong Li、Yuting Liu、Zhan Lu
DOI:10.1021/acscatal.1c02851
日期:2021.9.3
molecules undergo this cross-coupling reaction smoothly to afford chiral allylic compounds in up to 93% ee and >20/1 E/Z ratio under mild reaction conditions with good functional group tolerance. A triplet-energy-transfer-inhibiting strategy is developed for the stereoselective synthesis of alkenes under visible-lightphotocatalysis. The coordination pattern of nickel with chiral bis-imidazoline ligand has
报道了通过光氧化还原/镍催化的立体和对映选择性苄基 C-H 烯基化。容易获得的烷基苯和烯基溴化物,包括复杂的分子,在温和的反应条件下顺利地进行这种交叉偶联反应,以提供高达 93% ee 和 >20/1 E / Z比的手性烯丙基化合物,具有良好的官能团耐受性。开发了一种三重态能量转移抑制策略,用于在可见光光催化下立体选择性合成烯烃。基于非线性效应实验和 X 射线衍射,阐明了镍与手性双咪唑啉配体的配位模式。
作者:Debasish Kundu、Manisha Tripathy、Pintu Maity、Brindaban C. Ranu
DOI:10.1002/chem.201500058
日期:2015.6.8
Cobalt(II)‐catalyzed C(sp2)O cross‐coupling between aryl/heteroaryl alcohols and vinyl/aryl halides in the presence of CuI has been achieved underligand‐free conditions. In this reaction, copper plays a significant role in transmetalation rather than being directly involved in the CO coupling. This unique Co/Cu‐dual catalyst system provides an easy access to a library of aryl–vinyl, heteroaryl–styryl
protocol for the construction of 9-(diorganomethylidene)fluorenes through palladium-catalyzed coupling reactions of 2-iodobiphenyls with alkenyl bromides has been reported. The reaction proceeds through the C–H activation/oxidative addition/reduction elimination/intramolecular Heck coupling reaction to afford a series of 9-(diorganomethylidene)fluorenes with good yields. Control experiments demonstrate that
An unprecedented iron/palladium-catalyzed reductive cross-coupling of alkenylbromides and bromodifluoromethanes with manganese as the reductant has been disclosed. A variety of functional groups was well tolerated, providing various substituted gem-difluoroallylenes in moderate to good yields. The preliminary mechanism studies ruled out the radical pathway for this new reaction.