已经实现了高效的Cu(II)催化的马来酰亚胺自由基加成。鉴定出的铜催化剂可通过裂解酮肟中的O-H键,然后将自由基添加到N-取代的马来酰亚胺中,从而形成肟自由基(N-O )。通过EPR光谱和可变温度1 H NMR检测并确认了肟自由基(NO )。简单的一锅反应可轻松制备中度到良好收率的各种肟醚加合物产物。
A novel protocol for the activation of the Beckmannrearrangement utilizing the readily available and economical geminal dichloroimidazolidinediones (DCIDs) on a substoichiometric scale (10 mol %) has been developed. A unique self-propagating mechanism for the substoichiometric dichloroimidazolidinedione-activated transformation was proposed and validated. The substrate scope of the developed protocol
Rhodium‐Catalysed [4+2] Annulation of Aromatic Oximes with Terminal Alkenes by C−H/N−O Functionalization towards 3,4‐Dihydroisoquinolines
作者:Xu Zhang、Xuan‐Hui Ouyang、Yang Li、Bo Chen、Jin‐Heng Li
DOI:10.1002/adsc.201900922
日期:2019.11.5
Rhodium (Rh)‐catalysed [4+2] annulation of aromatic oximes with common terminal alkenes for the synthesis of 3,4‐dihydroisoquinolines is presented. Through the cooperation of a Rh(III) catalyst and a catalytic amount of K2HPO4 base, the reaction enables the formation of two new bonds, a C(sp2)−C(sp3) bond and a C(sp3)−N bond, in a single reaction via functionalization of both the C−H and N−O bonds
method for synthesis of oximes from aldehydes or ketones with N-hydroxyphthalimide or N-hydroxysuccinimide in water has been described. It is the first time to utilize NHPI as an oximation reagent to synthesize aldoximes and ketoximes from the corresponding organic carbonyl compounds without other reagents. The reaction tolerates various functional groups and affords the corresponding oximes in 76%–98% yields
An Electrochemical Beckmann Rearrangement: Traditional Reaction via Modern Radical Mechanism
作者:Li Tang、Zhi‐Lv Wang、Yan‐Hong He、Zhi Guan
DOI:10.1002/cssc.202001553
日期:2020.9.18
electrochemical Beckmannrearrangement, i. e. the direct electrolysis of ketoximes to amides, is presented for the first time. Using a constant current as the driving force, the reaction can be easily carried out under neutral conditions at room temperature. Based on a series of mechanistic studies, a novel radical Beckmannrearrangementmechanism is proposed. This electrochemical Beckmannrearrangement does