Oxidative Desulfurization-Fluorination of Methyl Arenedithiocarboxylates. A Convenient Synthesis of Trifluoromethylated Aromatic Compounds
作者:Manabu Kuroboshi、Tamejiro Hiyama
DOI:10.1246/cl.1992.827
日期:1992.5
Trifluoromethyl-substituted aromatic compounds were obtained by oxidativedesulfurization-fluorination reaction of methyl arenedithiocarboxylates using n-Bu4N+H2F3>− and 1,3-dibromo-5,5-dimethylhydantoin (DBH). Use of N-bromosuccinimide or N-iodosuccinimide instead of DBH afforded difluoro(methylthio)methyl-substituted aromatics.
A Facile Synthesis of Trifluoromethyl- and 3,3,3-Trifluoropropenyl-Substituted Aromatic Compounds by the Oxidative Desulfurization-Fluorination of the Corresponding Carbodithioates
作者:Satoru Furuta、Manabu Kuroboshi、Tamejiro Hiyama
DOI:10.1246/bcsj.72.805
日期:1999.4
Trifluoromethyl-substituted aromatic compounds were easily synthesized by the oxidativedesulfurization-fluorination reaction of readily accessible methyl arenecarbodithioates using [n-Bu4N]H2F3 and 1,3-dibromo-5,5-dimethylhydantoin (DBH) under extremely mild conditions. Use of N-bromosuccinimide or N-iodosuccinimide instead of DBH afforded difluoro(methylthio)methyl-substituted aromatics. In a similar
(4) eliminates N2 at −45 °C and generates thiobenzophenone S-methylide (5), which is intercepted by dipolarophiles. The 1,3-cycloadditions of 5 with thiones (aromatic and aliphatic thioketones, dithioesters, trithiocarbonate) furnish 1,3-dithiolanes 7, in which the substituents, even voluminous ones, appear in the proximal 4- and 5-positions. The reaction of 5 with adamantanethione furnishes 7h and
2,2-Diphenyl-1,3,4-thiadiazoline, prepared from thiobenzophenone and diazomethane at −78°C, extrudes N2 at −45°C and allows to study in situ 1,3-cycloadditions of thiobenzophenone S-methylide (3) with electrophilic CS, CC, CC, and NN bonds.
The activity scale of dipolarophiles versus thiobenzophenone s-methylide
作者:Rolf Huisgen、Li Xingya
DOI:10.1016/s0040-4039(00)88294-5
日期:——
Competition experiments of pairs of dipolarophiles for thiobenzophenone S-methylide () furnish relative rate constants which reveal an unusually high selectivity of the nucleophilic 1,3-dipole, in accordance with Sustmann's PMO concept.