Visible light-induced radical aryldifluoromethylation of N-arylacrylamides using [bis(difluoroacetoxy)iodo]benzene as a difluoromethylation reagent is reported for the first time. The inexpensive and readily accessible reagents and the mild reaction conditions render this method an alternative and practical strategy for the synthesis of difluoromethyl substituted oxindoles.
Aerobic Radical-Cascade Alkylation/Cyclization of α,β-Unsaturated Amides: an Efficient Approach to Quaternary Oxindoles
作者:Promita Biswas、Subhasis Paul、Joyram Guin
DOI:10.1002/anie.201603809
日期:2016.6.27
An efficient method for the aerobic radical‐cascade alkylation/cyclization of α,β‐unsaturated amides to afford functionalized oxindoles with a C3 quaternary stereocenter is described. The process is based on the generation of valuable alkyl radicalsthrough sustainable aerobic C−H activation of aldehydes followed by decarbonylation using O2 as the sole oxidant. This method features a broad substrate
Pd(0)-Catalyzed radical aryldifluoromethylation of activated alkenes
作者:Jian-Yong Wang、Yi-Ming Su、Feng Yin、Yan Bao、Xin Zhang、Yue-Ming Xu、Xi-Sheng Wang
DOI:10.1039/c3cc49315f
日期:——
intramolecular aryldifluoromethylation of activatedalkenes under mild reaction conditions has been developed. This reaction provides a new method for construction of a variety of difluoromethylatedoxindoles. Mechanistic investigations indicate that a difluoromethyl radical, which was triggered by Pd(0), initiated the cascade sequence through an addition to the alkene.
Iron-catalyzed radical aryldifluoromethylation of activated alkenes to difluoromethylated oxindoles
作者:Jian-Yong Wang、Xin Zhang、Yan Bao、Yue-Ming Xu、Xiu-Fen Cheng、Xi-Sheng Wang
DOI:10.1039/c4ob00758a
日期:——
An iron-catalyzed aryldifluoromethylation of activatedalkenes under mild reaction conditions has been developed, which is a rare example where a cosolvent is used to improve the reaction yield along with Fenton's reagent and thus provides an economic and green method for the synthesis of a variety of difluoromethylatedoxindoles. Preliminary mechanistic investigations indicate a radical addition path
The reaction of N-aryl acrylamides with maleimides in the presence of a ruthenium/rhodium catalyst and Cu(OAc)2·H2O provided succinimide-substituted oxindole derivatives in good to excellent yields. In the reaction, 3,3'-disubstituted oxindoles are produced via a C-H alkylation and intramolecular oxidative cyclization sequence. The proposed mechanism was supported by competition experiments, deuterium