Synthetic studies on O-heterocycles via cycloadditions. Part 1. Photochemical (electron transfer sensitised) C-C cleavage of diaryloxiranes
作者:Paul Clawson、Patricia M. Lunn、Donald A. Whiting
DOI:10.1039/p19900000153
日期:——
with naphthalene-1,4-dicarbonitrile as sensitiser in the presence of electron deficient dipolarophiles leads, via a presumed carbonyl ylide, to various dihydro- and tetrahydro-furans. This chemistry is extended, for the first time, to an example with both aryl rings oxygenated, 2,3-bis(p-methoxyphenyl)oxirane, using anthracene-9,10-dicarbonitrile as sensitiser; in contrast to stilbene oxide, in this
Redesign of a Pyrylium Photoredox Catalyst and Its Application to the Generation of Carbonyl Ylides
作者:Edwin Alfonzo、Felix Steven Alfonso、Aaron B. Beeler
DOI:10.1021/acs.orglett.7b01222
日期:2017.6.2
We report the exploration into photoredox generation of carbonylylides from benzylic epoxides using newly designed 4-mesityl-2,6-diphenylpyrylium tetrafluoroborate (MDPT) and 4-mesityl-2,6-di-p-tolylpyrylium tetrafluoroborate (MD(p-tolyl)PT) catalysts. These catalysts are excited at visible wavelengths, are highly robust, and exhibit some of the highest oxidation potentials reported. Their utility