Anomalous reactivity of radical cations produced by photosensitized oxidation of 4-methoxybenzyl alcohol derivatives: role of the sensitizer
作者:Tiziana Del Giacco、Annalisa Faltoni、Fausto Elisei
DOI:10.1039/b711541e
日期:——
tetrafluoroborate (NMQ(+)BF(4)(-)) as sensitizers. In particular, steady-state irradiation with DCA produced carbonyl compounds and, with NMQ(+)BF(4)(-), carbonyl compounds, ethers (substrates 1a-c ) and styrene (substrate 1d ) while time-resolved investigations gave evidence of charged species produced upon irradiation. The effect of solvent polarity on the reactivity was investigated; in the case of DCA
The dicationic diruthenium complex 1c (Ru-III-Ru-III) catalytically promotes the dimerization of alpha-methylstyrenes into the corresponding acyclic dimers, while the use of the mixed-valence diruthenium complex (Ru-III-Ru-IV) generated from 1c and cinnamyl chloride as an active catalyst affords the corresponding indanes via cyclization of the acyclic dimers. The selectivity of the catalytic dimerization of alpha-methylstyrenes depends on the nature of electrophilicity due to valence electrons in the diruthenium cores between Ru-III-Ru-III and Ru-III-Ru-IV.
Sequential olefination–dimerisation of benzylic dithioacetals by the nickel-catalysed reaction with methyl Grignard or zinc reagent
main group elements from cross-coupling reactions have been shown to serve as Lewisacids, mediating further reactions of organic coupling products. Thus, the nickel-catalysed olefination of benzylic dithioacetal with MeMgI in benzene in a sealed Schlenk tube at 130 °C generates magnesium mercaptide which regioselectively converts 2-arylpropene into a dimer in good yield. Aryl iodide reacts with 2-propenylmagnesium