我们报告了一种远程官能化策略,该策略允许通过 Ni 催化的链从远处的烯烃位点步行来Z选择性合成(杂)芳族和脂肪族酮的甲硅烷基烯醇醚。位置选择性由链游走的方向性控制,并且与所得甲硅烷基烯醇醚的热力学偏好无关。我们的机理数据表明,在这些条件下形成Ni (I)二聚体,作为催化剂静止状态,并在与烷基溴反应后转化为 [Ni (II) -H] 作为活性链行走/功能化催化剂,最终生成稳定的 η 3 键合Ni (II) 烯醇作为关键的选择性控制中间体。
novel and atom-economic palladium-catalyzed isomerization-hydrocarbonylative cyclization reaction of 1,5-dienes to 2-alkylidenecyclopentanones has been developed, which provides a rapid and straightforward approach to 2-alkylidenecyclopentanones with high stereoselectivity. The reaction was found to proceed via alkene isomerization and selective hydrocarbonylative cyclization to generate 2-alkylidenecyclopentanones
Selective Synthesis of <i>Z</i>-Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones
作者:Sinem Guven、Gourab Kundu、Andrea Weßels、Jas S. Ward、Kari Rissanen、Franziska Schoenebeck
DOI:10.1021/jacs.1c01797
日期:2021.6.9
the Z-selective synthesis of silyl enol ethers of (hetero)aromatic and aliphatic ketones via Ni-catalyzed chain walking from a distant olefin site. The positional selectivity is controlled by the directionality of the chain walk and is independent of thermodynamic preferences of the resulting silyl enol ether. Our mechanistic data indicate that a Ni(I) dimer is formed under these conditions, which
我们报告了一种远程官能化策略,该策略允许通过 Ni 催化的链从远处的烯烃位点步行来Z选择性合成(杂)芳族和脂肪族酮的甲硅烷基烯醇醚。位置选择性由链游走的方向性控制,并且与所得甲硅烷基烯醇醚的热力学偏好无关。我们的机理数据表明,在这些条件下形成Ni (I)二聚体,作为催化剂静止状态,并在与烷基溴反应后转化为 [Ni (II) -H] 作为活性链行走/功能化催化剂,最终生成稳定的 η 3 键合Ni (II) 烯醇作为关键的选择性控制中间体。
Visible-Light-Mediated Generation of Nitrogen-Centered Radicals: Metal-Free Hydroimination and Iminohydroxylation Cyclization Reactions
作者:Jacob Davies、Samuel G. Booth、Stephanie Essafi、Robert A. W. Dryfe、Daniele Leonori
DOI:10.1002/anie.201507641
日期:2015.11.16
formation and use of iminyl radicals in novel and divergent hydroimination and iminohydroxylationcyclizationreactions has been accomplished through the design of a new class of reactive O‐aryl oximes. Owing to their low reduction potentials, the inexpensive organic dye eosin Y could be used as the photocatalyst of the organocatalytic hydroiminationreaction. Furthermore, reaction conditions for a unique