Highly Stereoselective Formal [3 + 3] Cycloaddition of Enals and Azomethine Imines Catalyzed by <i>N</i>-Heterocyclic Carbenes
作者:Audrey Chan、Karl A. Scheidt
DOI:10.1021/ja0709167
日期:2007.5.1
are effective catalysts for generating homoenolate species from α,β-unsaturated aldehydes. The nucleophilic intermediate adds to azomethine imines, and the resulting activated carbonyl unit undergoes an intramolecular acylation event. This formal [3 + 3] cycloaddition between α,β-unsaturated aldehydes and azomethine imines catalyzed by NHC has been developed to give substituted pyridazinones in good to
The reactions between 5-substituted pyrazolidine-3-ones, aldehydes, and methyl methacrylate provided tetrahydropyrazolo[1,2-a]pyrazole-1-carboxylates as mixtures of syn- and anti-diastereomers. Testing for inhibition of dihydroorotate dehydrogenase of Plasmodium falciparum (PfDHODH) revealed high activity of some anti-isomers of the methylesters, while the corresponding carboxylic acids and carboxamides
作者:Can Li、Cong-Shuai Wang、Tian-Zhen Li、Guang-Jian Mei、Feng Shi
DOI:10.1021/acs.orglett.8b03604
日期:2019.2.1
A Brønstedacid-catalyzed (4 + 3) cyclization of N,N′-cyclic azomethine imines with isatoic anhydrides has been discovered, which constructs seven-membered nitrogenous heterocyclic frameworks with overall high yields (up to 98% yield). This reaction represents a rarely reported (4 + 3) cyclization of N,N′-cyclic azomethine imines, which involves the reassembly of a C–N bond. In addition, this reaction
Photocatalytic reductive radical–radical coupling of <i>N</i>,<i>N</i>′-cyclicazomethine imines with difluorobromo derivatives
作者:Peng-Ju Xia、Zhi-Peng Ye、Dan Song、Ji-Wei Ren、Han-Wen Wu、Jun-An Xiao、Hao-Yue Xiang、Xiao-Qing Chen、Hua Yang
DOI:10.1039/c8cc09385g
日期:——
A visible-light-induced difluoroalkylation of N,N′-cyclicazomethine imine was successfully realized through a novel photoredox radical–radical cross-coupling reaction. This developed protocol exhibits high functional group tolerance and affords a variety of difluorinated 3-pyrazolidinone scaffolds. Extensive mechanistic investigations have been undertaken, well revealing the involvement of a reductive
Carbamoylation of Azomethine Imines via Visible-Light Photoredox Catalysis
作者:Bianca T. Matsuo、Pedro H. R. Oliveira、José Tiago M. Correia、Márcio W. Paixão
DOI:10.1021/acs.orglett.1c02353
日期:2021.9.3
versatile and robust photocatalytic methodology to install the amide functional group into azomethineimine ions is described. This protocol is distinguished by its broad scope and mild reaction conditions, which are well suited for the preparation of structurally complex compounds in the form of amino acids, peptides, and small drug-like molecules. Moreover, the generated pyrazolidinone core could