CuI-Catalyzed Aerobic Oxidative α-Aminaton Cyclization of Ketones to Access Aryl or Alkenyl-Substituted Imidazoheterocycles
摘要:
CuI-catalyzed aerobic oxidative synthesis of imidazoheterocycles has been achieved. Four hydrogen atoms were removed in one step. This protocol was compatible with a broad range of functional groups, and it has been also successfully extended to unsaturated ketones, bringing about the formation of alkenyl-substituted imidazoheterocycles, which were difficult to prepare by previous means. Preliminary mechanistic studies indicated that this reaction was most likely to proceed through a catalytic Ortoleva-King reaction. By using this method, the marketed drug Zolimidine could be prepared with 90% yield on a gram scale from commercially available materials.
The Pd(ii)-catalyzed pyridine-directed carbonylative cycloamidation of ketoimines has provided an efficient protocol for assembly of pyrido[1,2-a]pyrimidin-4-ones.
The palladium-catalyzed oxidative [3+2] cycloaddition of ketoimines with alkynes provided an efficient access to multisubstituted pyrroles via Csp3–H activation.
Thiocarbonylation of C(sp3)-H bonds in pyridylamines with CS2: Facile synthesis of pyrido[1,2-a]pyrimidine-4-thiones
作者:Xiao-Yu Zhou、Xiang-Yu Li、Zhen Zhang、Da-Gang Yu
DOI:10.1016/j.cclet.2021.05.055
日期:2021.12
Herein, a facilesynthesis of valuable pyrido[1,2-a]pyrimidine-4-thiones is reported via novel thiocarbonylation of C(sp3)-H bonds with carbon disulfide (CS2). This reaction features easy availability of substrates, good functional group tolerance, high yields, facile scalability and atom economy. Mechanistic investigations indicate that sulfate anion and sulfuric anhydride anion might be involved