photochemical cross-coupling protocol towards bi(hetero)aryls has been developed. The coupling reactions were mediated by dicyanopyrazine photoredox catalyst, while a photoinduced disproportionation process has been identified as an accompanying mechanism, especially for pyrrole derivatives. The developed method allows the cross-coupling of five-membered rings such as pyrrole, imidazole, thiazole and
Catalytic amounts of 1,3-di(methyl)imidazole-2-ylidene, one of the simplest and most prototypical N-heterocyclic carbenes, can up-convert aldehydes into powerful stoichiometric sources of electrons (Super Electron Donors) for reductive transformations of iodoaryls (Ered < −2 V). In particular, the hydroarylation of 1,1′-diarylethylenes, which may require high temperatures and inherently generate stoichiometric
Rearrangemnets of organometallic compounds. 23. Carbon-skeletal [1,2] anionic and radical sigmatropic rearrangements: group migratory aptitudes as a probe of charge type in the 1,2-shifts of .beta.-phenyl-.beta.-(2-pyridyl)- and .beta.-phenyl-.beta.-(4-pyridyl)ethyl systems
作者:John J. Eisch、Csaba A. Kovacs、Prabodh Chobe、Marek P. Boleslawski
DOI:10.1021/jo00229a001
日期:1987.10
Channeling the SmI<sub>2</sub> Reactions to the Radical Path: Radicals Resisting Reduction by SmI<sub>2</sub>
作者:Ramesh Yella、Shmaryahu Hoz
DOI:10.1021/ol501490f
日期:2014.8.1
Studies on the reaction of 4-(2,2-diphenylvinyl)pyridine with SmI2 revealed that the intermediate radical strongly resists further reduction to the corresponding anion. The resistance of the radical to accepting another electron is traced to its stabilization by the nitrogen lone pair. The literature suggests that oxygen may also play a role similar to that of nitrogen in directing the course of the reaction toward radical rather than to anionic chemistry.
EISCH, JOHN J.;KOVACS, CSABA A.;CHOBE, PRABODH;BOLESLAWSKI, MAREK P., J. ORG. CHEM., 52,(1987) N 20, 4427-4437
作者:EISCH, JOHN J.、KOVACS, CSABA A.、CHOBE, PRABODH、BOLESLAWSKI, MAREK P.