Arylsulfur chlorotetrafluorides as useful fluorinating agents: Deoxo- and dethioxo-fluorinations

Usage of arylsulfur chlorotetrafluorides 1 as versatile deoxo- and dethioxo-fluorinating agents is described. There have been developed two convenient methods for the in situ preparation of reactive arylsulfur trifluorides 2 from 1. The one is reduction of 1 with a reducer such as pyridine to 2, and the other is disproportionation of 1 with a diaryl disulfide to 2 with evolution of chlorine gas. The latter method is a convenient way to get neat 2 from 1. The in situ prepared 2 fluorinates many kinds of substrates such as alcohols, aldehydes, ketones, diketones, and carboxylic acids to give the corresponding CF, CF2, CF2CF2, and CF3 compounds in high yields. 2 also fluorinates various sulfur compounds including CS groups to give CF2, OCF2, CF3, and OCF3 compounds in high yields. Reactions of 2 with diols or bis(trimethylsilyl) derivatives of diols or amino alcohols provided the corresponding deoxofluoro-arylsulfinylation products in high yields. In addition, it has been found that chlorotetrafluorides 1 directly and effectively react with the sulfur compounds to give the corresponding fluoro compounds in high yields. Since they are the intermediates for the production of industrially useful arylsulfur pentafluorides, arylsulfur chlorotetrafluorides 1, in particular, phenylsulfur chlorotetrafluoride (1a) are expected to find use as inexpensive and versatile deoxo- and dethioxo-fluorinating agents for the preparation of many organofluoro compounds.