Directed ortho Metalation of<i>O</i>-Aryl and<i>O</i>-Pyridyl Thiocarbamates. A Versatile Synthetic Method for Substituted Phenol into Thiophenol Conversion
作者:Francis Beaulieu、Victor Snieckus
DOI:10.1055/s-1992-34150
日期:——
The preparation of ortho-substituted O-aryl and O-pyrid-3-yl thiocarbamates 7a-h and 11a-d and anionic ortho-Fries rearrangements of selected cases, [O-phenyl N,N-diethylthiocarbamate (6a) → N,N-diethyl-2-hydroxy-3-methylbenzenecarbothioamide (9), O-[4-(trimethylsilyl)pyridyl-3-yl] N,N-diethylthiocarbamate (11a) → N,N-diethyl-3-hydroxy-4-(trimethylsilyl)pyridine-3-carbothioamide (13)], via the directed ortho metalation protocol are described; coupled with their further thermal conversion (Kwart-Newman rearrangement) into S-thiocarbamate 8a-f and 12a-b and simple hydrolysis, this constitutes a new methodology for phenol to ortho-substituted thiophenol conversion (4 → 5).
描述了正位取代的O-芳基和O-吡啶-3-基硫氨基甲酸酯7a-h和11a-d的制备,以及选择性案例的阴离子正位弗里斯重排反应,[O-苯基N,N-二乙基硫氨基甲酸酯(6a) → N,N-二乙基-2-羟基-3-甲基苯硫酰胺(9),O-[4-(三甲基硅基)吡啶-3-基] N,N-二乙基硫氨基甲酸酯(11a) → N,N-二乙基-3-羟基-4-(三甲基硅基)吡啶-3-硫酰胺(13)],通过定向正位金属化的程序进行;结合其进一步的热转化(Kwart-Newman重排)为S-硫氨基甲酸酯8a-f和12a-b以及简单水解,这构成了一种从酚转化为正位取代硫酚的新方法(4 → 5)。