Photo-Induced Formal Trifluoropropanation of Organic Halides

Abstract

CF3-containing molecules are frequently encountered in many best-selling pharmaceutical drugs. Consequently, a large number of methods have been developed for introducing a CF3 group into organic compounds. However, innovative protocols enabling direct access to alkyl-CF3 moieties are still sought after. In this context, we report a visible-light-induced formal trifluoropropanation of various alkyl and aryl halide derivatives using the 2-Bromo-3,3,3-trifluoro-1-propene (BTP) as a readily available building block. Our strategy relies on the use of a catalytic system merging a catalytic amount of supersilane and NaBH4 as an additional reductant. These mild reaction conditions are compatible with a large range of functional groups. Finally, double deuterium incorporation was obtained upon replacement of NaBH4 with NaBD4 under these catalytic conditions, leading to the formation of hitherto unknown α,α-d 2-CF3 compounds.

Solvent-Controllable C–F Bond Activation for Masked Formylation of α-Trifluoromethyl Alkenes via Organo-Photoredox Catalysis

“…Apart from α-trifluoromethyl (hetero)­aryl alkenes, trifluoromethyl eneyne was also competent substrate, thus furnishing the difluoroalkene 2z with excellent regioselectivity, albeit in low yield. It was worth mentioning that the functionalization of α-trifluoromethyl alkenes with intact trifluoromethyl group in the product still remains a challenge . Herein, substrate containing a strongelectron-withdrawing aldehyde group chemo-selectively proceeded the hydroformylation pathway to afford 4 as single product in 65% yield, which was in contrast to the defluoro-formylation pathway in most cases.…”

Photocatalyzed Amination of Alkyl Halides to Access Primary Amines

“…They were purchased from Sigma-Aldrich, Alfa Aesar, Fluorochem, and TCI Europe and used without further purification. Starting materials 2c , 2e , 2f , 2g , 2h , 2i – 2j , 2l-I , 2m - 2o , 2t - 2v , and 2w were synthesized according to described procedures.…”

Photocatalyzed Formation of gem‐Difluoroalkenes Using Oxime Esters

“…Concomitantly to this work, we have demonstrated that light-induced radical β-bromo or iodo fragmentation can be key to achieving hydrohalogenation of unsaturated compounds under visiblelight irradiation. [15] In this context and given our recent interest for fluorination reactions, [16] we envisaged to explore the possibility of synthesizing gem-difluoroal-kenes by the use of readily available oxime ester derivatives and 1-bromo-1,1-difluoroprop-2-ene (BDFP). Indeed, such oximes have recently been shown to be efficient radical precursors for achieving a large panel of organic reactions.…”