Selective Oxidative [4+2] Imine/Alkene Annulation with H<sub>2</sub>
Liberation Induced by Photo-Oxidation
作者:Xia Hu、Guoting Zhang、Faxiang Bu、Aiwen Lei
DOI:10.1002/anie.201711359
日期:2018.1.26
The oxidative [4+2] annulationreaction represents an elegant and versatile syntheticprotocol for the construction of six‐membered heterocyclic compounds. Herein, a photoinduced oxidative [4+2] annulation of NH imines and alkenes was developed by utilizing a dual photoredox/cobaloxime catalytic system. Various multisubstituted 3,4‐dihydroisoquinolines can be obtained in good yields. This method is
BF3·OEt2-mediated cycloaddition of O-tert-butyldimethylsilyloximes having olefin moieties: intramolecular cycloaddition of N-borano-nitronesElectronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b2/b201423h/
Treatment of O-tert-butyldimethylsilyloximes having olefin moieties in the molecules with BF3.OEt2 results in efficient generation of N-borano-nitrones, which undergo intramolecularcycloaddition at room temperature to afford N-nonsubstituted cycloadducts after work-up.
A photoinduced, photocatalyst-free cyanoalkylation of nitrostyenes was explored, affording a series of cyanoalkylated alkenes in moderate to good yields. Mechanistic studies reveal that an electron donor–acceptor complex formed between O-aryl oximes and DIPEA is presumably involved in this process. The excellent functional group compatibility of this newly designed synthetic protocol allows for cyanoalkylation
Diboron-promoted iron-catalyzed denitrative vinylation of β-nitrostyrenes with cycloketoximes
作者:Dingcheng Shi、Xingxuan Xia、Binlin Zhao、Yu Yuan
DOI:10.1039/d3ob00890h
日期:——
We have developed a new iron-catalyzed ring opening alkenylation of cycloketoximes with β-nitrostyrenes for the facile synthesis of flexible distal cyanoalkyl alkenes. Both non-active strained cycloketoximes and less-strained cycloketoximes could be coupled with β-nitrostyrenes with excellent regio- and stereoselectivity under base-free redox-neutral conditions. The diboron reagent played an irreplaceable