Metal‐free photochemical carbene‐transfer reactions of tosylhydrazones were developed under blue light irradiation at room temperature. This reaction constructs C−X (X=C, N, O, S) bonds and cyclopropanes from readily available and stable starting materials.
Blue light-promoted photolysis of aryldiazoacetates
作者:Igor D. Jurberg、Huw M. L. Davies
DOI:10.1039/c8sc01165f
日期:——
Aryldiazoacetates can undergo photolysis under blue light irradiation (460–490 nm) at room temperature and under air in the presence of numerous trapping agents, such as styrene, carboxylic acids, amines, alkanes and arenes, thus providing a straighforward and general platform for their mild functionalization.
Carbon–carbon bond-forming reactions of α-carbonyl carbocations: exploration of a reversed-polarity equivalent of enolate chemistry
作者:Ping-Shan Lai、Joshua A. Dubland、Mohammed G. Sarwar、Michael G. Chudzinski、Mark S. Taylor
DOI:10.1016/j.tet.2011.07.065
日期:2011.9
Carbon–carbon bond-forming reactions of putative α-carbonyl carbocation intermediates generated by Lewis acid- or silver-promoted ionizations of toluenesulfonate or halide leaving groups are described. This under-exploited mode of reactivity represents an ‘umpolung’ of conventional enolate chemistry, and enables C–C bond construction in both intra- and intermolecular contexts. Attempts to develop diastereoselective
Photocatalytic Alkylation of Pyrroles and Indoles with α-Diazo Esters
作者:Łukasz W. Ciszewski、Jakub Durka、Dorota Gryko
DOI:10.1021/acs.orglett.9b02612
日期:2019.9.6
electron-rich aromatic compounds with diazo esters. C-2-alkylated indoles and pyrroles are obtained with good yields even though the photocatalyst loading is as low as 0.075 mol %. For EWG-substituted substrates, the addition of a catalytic amount of N,N-dimethyl-4-methoxyaniline is required. Both EWG-EWG- and EWG-EDG-substituted diazo esters are suitable as alkylatingagents. The reaction selectivity and mechanistic
Tridentate Nickel(II)-Catalyzed Chemodivergent C–H Functionalization and Cyclopropanation: Regioselective and Diastereoselective Access to Substituted Aromatic Heterocycles
作者:Ekta Nag、Sai Manoj N. V. T. Gorantla、Selvakumar Arumugam、Aditya Kulkarni、Kartik Chandra Mondal、Sudipta Roy
DOI:10.1021/acs.orglett.0c02138
日期:2020.8.21
Schiff-base nickel(II)-phosphene-catalyzed chemodivergent C–H functionalization and cyclopropanation of aromatic heterocycles is reported in moderate to excellent yields and very good regioselectivity and diastereoselectivity. The weak, noncovalent interaction between the phosphene ligand and Ni center facilitates the ligand dissociation, generating the electronically and coordinativelyunsaturated active