Photochemical Reactivity of 1-Substituted-1-aza-1,4-dienes Promoted by Electron-Acceptor Sensitizers. Di-π-methane Rearrangements and Alternative Reactions via Radical-Cation Intermediates
作者:Diego Armesto、Maria J. Ortiz、Antonia R. Agarrabeitia、Santiago Aparicio-Lara、Mar Martin-Fontecha、Marta Liras、M. Paz Martinez-Alcazar
DOI:10.1021/jo026440l
日期:2002.12.1
series of beta,gamma-unsaturated imines, oxime acetates, and oxime methyl ethers, using 9,10-dicyanoanthrathene (DCA) or dicyanodurene (DCD) as electron acceptor sensitizers, affords the corresponding cyclopropanes resulting from 1-aza-di-pi-methane rearrangements via radicalcations. In some cases, alternative reactions of these intermediates occur to yield nitriles, dihydroquinolines, dihydronaphthalene
bromides has been established. The reaction exhibits high compatibility with a wide range of terminal alkynes and diverse aryl boronic acids, thus providing facile access to various stereodefinedtrisubstitutedalkenes in high yield under mild reaction conditions. Preliminary mechanistic investigations support the formation of alkyl radicals and their subsequent addition to alkynes in the reaction
PRATT A. C.; ABDUL-MAJID O., J. CHEM. SOC. PERKIN TRANS.,(1987) N 2, 359-364
作者:PRATT A. C.、 ABDUL-MAJID O.
DOI:——
日期:——
Novel Photoreactions of 2-Aza-1,4-dienes in the Triplet Excited State and via Radical-Cation Intermediates. 2-Aza-di-π-methane Rearrangements Yielding Cyclopropylimines and<i> N</i>-Vinylaziridines
作者:Diego Armesto、Olga Caballero、Maria J. Ortiz、Antonia R. Agarrabeitia、Mar Martin-Fontecha、M. Rosario Torres
DOI:10.1021/jo034452g
日期:2003.8.1
2-aza-1,4-dienes, by using 9,10-dicyanoanthracene (DCA) as an electron-acceptor sensitizer and biphenyl as cosensitizer, brings about regioselective formation of N-vinylaziridines. Under these conditions, azadiene 1 also affords cyclopropylimine 37, resulting from an aryl-di-pi-methane rearrangement. This result demonstrates that di-pi-methane reactions can also take place via radical-cation intermediates