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。
Palladium-Catalyzed Hydrocarbonylative Cyclization of 1,5-Dienes
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
Iron-catalyzed acylation-functionalization of unactivated alkenes with aldehydes
作者:Tian Tian、Xin Wang、Leiyang Lv、Zhiping Li
DOI:10.1039/d0cc06774a
日期:——
Herein, an iron-catalyzed acylation-functionalization of unactivatedalkenes with aldehydes via distal group ipso-migration is reported. This strategy overcame the energy barrier and reversibility in the difunctionalization of unactivatedalkenes with nucleophilic acyl radicals, and a variety of β-heteroarylated, -cyanated and -oximated unsymmetrical 1,6- and 1,7-diketones were obtained regioselectively
Herein we describe a nickel-catalyzed remote hydrosilylation of unconjugated enones with bulky triphenylsilane. A range of Z-silyl enolethers are obtained as major isomers due to the process of nickel triggered alkene isomerization. Notably, some specific alkyl silyl enolethers can be prepared from this protocol, which are not easily accessed by the traditional strategy using a strong base and chlorosilane
Bromoetherification of Alkenyl Alcohols by Aerobic Oxidation of Bromide: Asymmetric Synthesis of 2‐Bromomethyl 5‐Substituted Tetrahydrofurans
作者:Akihiko Tomizuka、Katsuhiko Moriyama
DOI:10.1002/adsc.201801557
日期:2019.3.15
An asymmetricsynthesis of 2‐bromomethyl‐5‐substituted tetrahydrofurans via a chiral‐ruthenium‐catalyzed transfer hydrogenation of 3‐butenyl ketones and bromoetherification of chiral pentenyl alcohols was developed. The inhibition of some side reactions furnished the desired products in high yields with high enantioselectivities. In addition, chiral pentenyl alcohols bearing electron‐donating groups