91083-69-1Relevant academic research and scientific papers
Comportement anodique particulier d'alkyl (aryl) oxy-1 triaryl-1,2,2 ethylenes, en presence de bases solubles et insolubles
Cariou, Michel
, p. 1015 - 1021 (2007/10/02)
The electrooxidation of 1-alkyl (aryl) oxy-1,2,2-triarylethylenes, with LiClO4 as supporting electrolyte, led to unexpected compounds resulting from the reaction of electrogenerated species on the base added in the anodic compartment.Thus, 1-methoxy-1,2,2-triphenylethylene 1a, by electrooxidation in acetonitrile, in the presence of 2,6-lutidine, led exclusively to an N-aryl substituted pyridinium perchlorate 6a.On the other hand, the expected methoxy-ketone 4 was mainly formed if the electrooxidation was carried out in the presence of either 2,6-di-tert-butyl-4-methyl-pyridine or K2CO3, or else if the phenyl groups are methoxylated in the para position (compound 1b).The 1-phenoxy-1,2,2-triphenyl-ethylene 2 led to the same results, whereas a cyclization reaction could have been expected.In the same way, the corresponding non-alkoxylated product, 1,1,2-triphenyl-ethylene 3, by electrooxidation in the presence of 2,6-lutidine, led to an N-vinyl substituted lutidinium perchlorate 10.In methanol, in the presence of K2CO3, the electrooxidation of enol ether 1a led to the mixture of the expected dimethoxylated product 11 and dioxolane 12; in the presence of 2,6-lutidine, dimethoxylation of the ethylenic double bond is accompanied by partial para-methoxylation of an aromatic ring that led to compound 13.
Degenerate β-Aryl Rearrangements in Photochemically Generated Triarylvinyl Cations
Kitamura, Tsugio,Kobayashi, Shinjiro,Taniguchi, Hiroshi,Fiakpui, Charles Y.,Lee, Choi Chuck,Rappoport, Zvi
, p. 3167 - 3170 (2007/10/02)
Irradiation of triphenyl- (1a), tri-p-tolyl (1b),or tri-p-anisylvinyl bromide (1c) in methanol gave the vinyl ethers 4 and the phenanthrenes 5.A study of -labeled bromides showed that β-aryl rearrangements takes place in the photochemically generated vinyl cations 3*.Irradiation of triaryl bromides 1* in trifluoroethanol and analysis of the extent of scrambling from C-2 to C-1 in the trifluoroethyl vinyl ethers 8 showed 38percent, 72percent, and 92percent rearrangement of the 13C label for 1a*, 1b*, and 1c*, respectively.Similar irradiation of 1* in methanol resulted in no rearrangement in 4.The results are discussed in relation to the nature of the solvent, the stability of the triarylvinyl cations, and the migratory aptitudes of the aryl groups.The behavior of the photochemically and thermally generated ions was compared.
