第一次证明了可见光诱导的由水性氧化硫叶立德形成的光氧化还原碳自由基。虽然通过 H 2 O直接还原氧化亚硝基有效地生成相应的碳氢化合物,但使用额外的烯烃作为自由基受体会改变化学反应性以实现N-芳基丙烯酰胺的烯烃碳芳基化。机理研究揭示了两种不同的反应途径,这些反应途径参与了水性氧化硫叶立德的碳自由基形成,导致还原释放二甲砜和碳芳基化形成 DMSO。
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.
Microwave-Assisted Copper-Catalyzed Oxidative Cyclization of Acrylamides with Non-Activated Ketones
作者:Yaping Zhao、Nandini Sharma、Upendra K. Sharma、Zhenghua Li、Gonghua Song、Erik V. Van der Eycken
DOI:10.1002/chem.201504776
日期:2016.4.18
An operationally simple and efficient microwave‐assisted protocol for the oxidative cyclization of acrylamide derivatives with non‐activated ketones to generate 3,3‐disubstituted oxindoles is described. The reaction proceeds by a copper‐catalyzed tandem radical addition/cyclization strategy and tolerates a series of functional groups with moderate to excellent yields.
A mild visible-light induced 4CzIPN/H+ photoredox system has been developed that enables hydroxyketones serving as a carbon radical precursor via formal C−O bond cleavage. This process was successfully exploited in the coupling/cyclization reaction of N-arylacrylamides and thereby provided a viable access to acyl oxindoles. This protocol features advantages including no need for any metal catalyst
已开发出一种温和的可见光诱导 4CzIPN/H +光氧化还原系统,使羟基酮能够通过正式的 C−O 键裂解充当碳自由基前体。该过程已成功用于 N-芳基丙烯酰胺的偶联/环化反应,从而为酰基羟吲哚提供了可行途径。该方案的优点包括不需要任何金属催化剂和添加剂、高产率、广泛的底物范围、克可扩展性以及 H 2 O 作为唯一副产物的释放。