Synthesis of Substituted 1,4,5,6-Tetrahydrocyclopenta[b]pyrroles by Platinum-Catalyzed Cascade Cyclization/Ring Expansion of 2-Alkynyl-1-azaspiro[2.3]hexanes
摘要:
The reaction of 2-allcynyl-1-azaspiro[2.3]hexanes with a platinum catalyst is described. 1,4,5,6-Tetrahydrocyclopenta[b]pyrroles having a variety of substituents were conveniently synthesized via a cascade cyclization/ring-expansion process.
General and selective reductive amination of carbonyl compounds using a core–shell structured Co<sub>3</sub>O<sub>4</sub>/NGr@C catalyst
作者:Tobias Stemmler、Felix A. Westerhaus、Annette-Enrica Surkus、Marga-Martina Pohl、Kathrin Junge、Matthias Beller
DOI:10.1039/c4gc00536h
日期:——
The application of heterogenized non-noble metal-based catalysts in selective catalytic hydrogenation processes is still challenging. In this respect, the preparation of a well-defined cobalt-based catalyst was investigated by immobilization of the corresponding cobalt(II)-phenanthroline-chelate on Vulcan XC72R carbon powder. The formed coreâshell structured cobalt/cobalt oxide nanocomposites are encapsulated by nitrogen-enriched graphene layers. This promising cheap heterogeneous catalyst allows for an efficient domino reductive amination of carbonyl compounds with nitroarenes.
Herein we report a novel palladium-catalyzedoxidativecarbonylation reaction for the synthesis of phthalimides with high atom- and step-economy. In our strategy, the imine and H2O, which are generated in situ from the condensation of aldehyde and amine, serve as self-sufficient directing group and nucleophile, respectively. This method provides rapid access to phthalimides starting from readily available
Metal-free aerobic oxidative coupling of amines in dimethyl sulfoxide via a radical pathway
作者:Mu Lin、Zikuan Wang、Huayi Fang、Lianghui Liu、Haolin Yin、Chun-Hua Yan、Xuefeng Fu
DOI:10.1039/c5ra25434e
日期:——
Metal-free oxidative coupling of amines is achieved simply by heating their dimethyl sulfoxide (DMSO) solution under oxygen as oxidant without any other catalysts or additives, accompanied by the formation of an equimolar amount of dimethyl sulfone (DMSO2). EPR experiments indicate that the reaction proceeds via a radical pathway. DMSO may play a triple role as solvent, radicalinitiator and co-reductant
“azole-including” cyclic anhydrides in the Castagnoli–Cushman reaction with imines, a remarkably reactive, pyrrole-based anhydride has been identified. It displayed a remarkably efficient reaction with N-alkyl and N-aryl imines, in particular, with “enolizable” α-C-H imines which typically fail to react with a majority of known cyclic anhydrides. The reactivity of this anhydride has been justified by
o-Phenylenediacetic Acid Anhydride in the Castagnoli–Cushman Reaction: Extending the Product Space to ε-Lactams
作者:Mikhail Krasavin、Olga Bakulina、Dmitry Dar’in
DOI:10.1055/s-0036-1588714
日期:2017.6
The diversity of lactam products accessible by the Castagnoli–Cushman reaction (CCR) of imines and dicarboxylic acid anhydrides has been extended to privileged e-lactams. This novel variant of the CCR using o-phenylenediacetic anhydride is often high-yielding and remarkably diastereoselective and allows the use of α-C–H imines.