Development of Stable Carbanionic Substituents.

During the past decade, carbon (C-H) acids depicted as 'Tf 2 CHR' (Tf=CF 3 SO 2 ) have attracted considerable attention as a new class of superacidic molecules, which show stronger acidity than sulfuric acid molecules. In recent years, the author has developed a synthetic methodology for such strong acids and has opened the door to chemistry of highly stabilised carbanions [Tf 2 CR] - , which are the conjugate bases of the carbon acids. These carbanion-containing salts are stable and easy-to-handle species. Our efforts have revealed that the ionic but lipophilic characters of this type of carbanion can be used as a unique 'substituent' for increasing both the water solubility and the lipophilicity of organic compounds. This Personal Account provides an overview of our [Tf 2 CR] - chemistry, including its synthesis, structure, reactivity, and applications.