Synthesis of Organofluorine Compounds with Acylsilanes

Comprehensive Summary,Organofluorine compounds are central in synthetic chemistry,medicinal chemistry and material chemistry.In this review,we summarize the investigations on the synthesis of organofluorine compounds with acylsilanes.For the non-fluorinated acylsilanes,the in situ generation of difluoroenoxysilanes from the reactions of the acylsilanes with trifluoromethylation reagents is the major pathway,leading to the facile preparation of variousα,α-difluoroketones.For the fluoroalkylacylsilanes,apart from the in situ generation of difluoroenoxysilanes through anion Brook rearrangement,radical Brook rearrangement of the photoexcited acylsilanes and the selective control of reactivities of the biradicals pave the way for the synthesis of a variety of organofluorine compounds.In general,most of these reactions gave racemic products,and the asymmetric synthesis of organofluorine compounds with acylsilanes is still rare,which would be a future.

Divergent Synthesis of Organofluorinated Molecules from Titanium Mediated Deoxygenation of Free Alcohols

Comprehensive Summary Alcohols as among the most widely occurring organic compounds known,deoxygenative transformations of free alcohols as partners in radical addition reactions remain formidable challenges with great opportunities to achieve new and useful transformations.Herein,we report a protocol via C—O bond cleavage and C—C bond-forming reaction of trifluoromethyl alkenes with free alcohols assisted by titanium reagents via a deoxygenative radical strategy,enabling the divergent synthesis for functional-group-rich organofluorinated compounds in high efficiencies.In this transformation,tertiary alcohols by Ti-catalysis could be converted to trifluoromethyl alkanes without defluorination in acidic conditions,while benzyl alcohols are employed by Ti-mediated activation to supply the gem-difluoroalkenes with defluorination in the presence of a base.This protocol is applicable for a broad range of trifluoromethyl alkenes with good functional group tolerance and a variety of tertiary alcohols and benzyl alcohols(including primary。

Ring opening of sugar-derived epoxides by TBAF/KHF_2:An attractive alternative for the introduction of fluorine into the carbohydrate scaffold

A stable and commercially available reagent mixture,composed of tetrabutylammonium bifluoride/potassium bifluoride（TBAF/KHF_2）,was found to be effective for the nucleophilic ring opening reactions of sugar-derived epoxides with fluoride.Different sugar-derived epoxide precursors,including 1-thioglycosides can be ring-opened to afford fluorinated carbohydrate products in high yields and in short reaction times.