Direct synthesis of N-heterocycles via the acceptorless dehydrogenative coupling is very challenging and scarcely reported under 3d transition-metal catalysis. Here, we have developed an efficient Mn(I)-catalyzed sustainable synthesis of various quinoxalines from 1,2-diaminobenzenes and 1,2-diols via the acceptorless dehydrogenative coupling reaction. Further, this strategy was successfully applied
Dehydrogenation of Nitrogen Heterocycles Using Graphene Oxide as a Versatile Metal-Free Catalyst under Air
作者:Jingyu Zhang、Shiya Chen、Fangfang Chen、Wensheng Xu、Guo-Jun Deng、Hang Gong
DOI:10.1002/adsc.201700178
日期:2017.7.17
Graphene oxide (GO) has been developed as an inexpensive, environmental friendly, metal‐free carbocatalyst for the dehydrogenation of nitrogenheterocycles. Valuable compounds, such as quinoline, 3,4‐dihydroisoquinoline, quinazoline, and indole derivatives, have been successfully used as substrates. The investigation of various oxygen‐containing molecules with different conjugated systems indicated
aerobic oxidative dehydrogenation of N-heterocycles were examined in detail. Many tetrahydroquinoline derivatives and a broad range of other N-heterocycles could be tolerated by the catalytic system using a biomass-derived solvent as a reaction medium. Newly generated mixed crystal phases, noticeably enhanced surface areas and labile lattice oxygen of the OMS-2-based nanocomposite catalysts might contribute
general alkylation of heterocycles using a simple palladium catalyst is reported. Most classes of heterocycles, including indoles and pyridines, efficiently coupled with unactivated secondary and tertiary alkylhalides. An alkyl radical addition to neutral heteroarenes is most likely involved.
Acceptorless dehydrogenative synthesis of 2-substituted quinazolines from 2-aminobenzylamine with primary alcohols or aldehydes by heterogeneous Pt catalysts
作者:Chandan Chaudhari、S. M. A. Hakim Siddiki、Masazumi Tamura、Ken-ichi Shimizu
DOI:10.1039/c4ra09205h
日期:——
CeO2-supported Pt nanoparticle catalysts enabled the acceptorless dehydrogenative synthesis of 2-substituted quinazolines from 2-aminobenzylamine with aliphatic and benzyl primary alcohols or aldehydes with low catalyst loading, wide substrate scope and good catalyst reusability, demonstrating the first acceptor-free and additive-free catalytic system for this reaction.
CeO 2负载的Pt纳米颗粒催化剂能够由2-氨基苄胺与脂肪族和苄基伯醇或醛进行无受体脱氢合成,具有低催化剂载量,广泛的底物范围和良好的催化剂可重复使用性,证明了第一种无受体和添加剂的化合物此反应的无催化体系。