is one of the most attractive catalysts, especially for aromatic C–H functionalizations. However, stoichiometric amounts of oxidants and strong carbanions are required, and C–H tertiary alkylation, especially with electron-deficient alkylgroups, is unexplored. In this paper, we describe the development of iron-catalyzed selective C–H tertiary alkylations with heteroaromatics, in which an iron salt
Palladium-Catalyzed Oxidative Difunctionalization of Alkenes with α-Carbonyl Alkyl Bromides Initiated through a Heck-type Insertion: A Route to Indolin-2-ones
作者:Jian-Hong Fan、Wen-Ting Wei、Ming-Bo Zhou、Ren-Jie Song、Jin-Heng Li
DOI:10.1002/anie.201402893
日期:2014.6.23
palladium‐catalyzed oxidative difunctionalization reaction of alkenes with α‐carbonyl alkyl bromides is described, in which the σ‐alkyl palladium(II) intermediate is generated through a Heck insertion and trapped using an aryl C(sp2)H bond. This method can be applied to various α‐carbonyl alkyl bromides, including primary, secondary, and tertiary α‐bromoalkyl esters, ketones, and amides.
Construction of Quaternary Carbon Center via NHC Catalysis Initiated by an Intermolecular Heck-Type Alkyl Radical Addition
作者:Lanjun Su、Huan Sun、Jikai Liu、Chengming Wang
DOI:10.1021/acs.orglett.1c01400
日期:2021.6.18
A quaternary carbon center containing an oxindole motif is constructed via NHC-catalyzed transition-metal and aldehyde-free intermolecular Heck-type alkyl radical addition initiated annulation. This redox-neutral protocol also features a simple procedure, broad substrate scope, good functional group tolerance and could be smoothly amplified to a gram scale. The mechanism study shows that the reaction
含有羟吲哚基序的季碳中心是通过 NHC 催化的过渡金属和无醛分子间 Heck 型烷基自由基加成引发的环化构建的。这种氧化还原中性方案还具有程序简单、底物范围广、官能团耐受性好并且可以顺利放大到克级的特点。机理研究表明,该反应可能经历了两次 SET 过程,其中涉及 NHC 自由基阳离子中间体。
Palladium-Catalyzed Oxidative Heck-Type Alkylation/Aryl Migration/Desulfonylation between Alkenes with α-Carbonyl Alkyl Bromides
作者:Jian-Hong Fan、Ji Yang、Ren-Jie Song、Jin-Heng Li
DOI:10.1021/ol503660a
日期:2015.2.20
A new Pd(II)-catalyzed alkene oxidative difunctionalization initiated by Heck insertion has been developed for the selective synthesis of acyclic and cyclic all-carbon quaternary stereocenters, which achieves an oxidative Heck-type alkylation, aryl migration, and desulfonylation sequence and represents a different input from those previously used Heck coupling in synthesis is reported.