Electrosynthesis 2.0 in 1,1,1,3,3,3-hexafluoroisopropanol/amine mixtures

Abstract

The intention of this review is to highlight the innovative electrolyte combination of 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) with tertiary nitrogen bases in electro-organic synthesis. This easy applicable and promising mixture is not yet well established in electro-organic synthesis, but expands the various possibilities in the latter. Combinations of fluorinated alcohols with nitrogen bases form highly conductive electrolyte systems, which can be evaporated completely. Consequently, no additional supporting electrolyte is required and work-up procedures are tremendously simplified. With this electrolyte mixture carbon-carbon homo- and cross-coupling reactions of arenes and phenols have been established with substrates that have not been previously susceptible to the anodic dehydrogenative coupling reaction. The intermediate installation of highly fluorinated alkoxy moieties can be exploited for subsequent conversions as well as various benzylic functionalization, including asymmetric transformations. These transformations show unique selectivity and functional group tolerance making them highly applicable to the synthesis of sophisticated structural motifs, including natural products.