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。
An α‐Cyclopropanation of Carbonyl Derivatives by Oxidative Umpolung
作者:Adriano Bauer、Giovanni Di Mauro、Jing Li、Nuno Maulide
DOI:10.1002/anie.202007439
日期:2020.10.5
nucleophiles is often associated with umpolung and cationic mechanisms. Herein, we report a general process converting a range of ketone derivatives into α‐cyclopropanated ketones by oxidative umpolung. Mechanistic investigation and careful characterization of side products revealed that the reaction follows an unexpected pathway and suggests the intermediacy of non‐classical carbocations.
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
Synthesis of ketones and aldehydes via reactions of Weinreb-type amides on solid support
作者:Tam Q Dinh、Robert W Armstrong
DOI:10.1016/0040-4039(95)02400-x
日期:1996.2
Ketones and aldehydes were formed in low to good yields in reactions of Weinreb-type amides on solidsupport and no overaddition occurred.
在固体载体上Weinreb型酰胺的反应中,酮和醛的生成率低至良好,并且没有发生过量加成反应。
Kinetic Resolution of Aminoalkenes by Asymmetric Hydroamination: A Mechanistic Study
作者:Alexanderâ L. Reznichenko、Frank Hampel、Kaiâ C. Hultzsch
DOI:10.1002/chem.200902229
日期:2009.11.23
complex for 1‐alkylaminopentenes diminishes resolution efficiency. Nevertheless, the relative cyclization rate for the two diastereomeric substrate–catalyst complexes remains in a typical range of 7–10:1. Plausible attractive π interactions between the aryl substituent and either the metal center or the aromatic system of the bis(triarylsilyl)‐substituted binaphtholate ligand may explain increased stability