Stereoconvergent Synthesis of Monofluoroalkenes via Photoinduced Dual Decarboxylative Cross-Coupling of α-Fluoroacrylic Acids with Redox-Active Esters

Abstract

Herein, a new strategy for the synthesis of monofluoroalkenes via employing α-fluoroacrylic acids and N-hydroxyphthalimide (NHPI) redox-active esters as coupling partners has been developed. This decarboxylative reaction enabled the formation of C­(sp2)–C­(sp3) bonds to provide a practical and efficient approach for the construction of a variety of monofluoroalkenes, which are key structural motifs in organic chemistry, under mild reaction conditions. The protocol exhibited excellent functional group compatibility and delivered monofluoroalkene products with excellent Z-stereoselectivity. This work also provides a platform for the modification of complex biologically active molecules containing carboxylic acids.

Recent advances in catalytic decarboxylative transformations of carboxylic acid groups attached to a non-aromatic sp2or sp carbon

“…An additional literature survey indicates that photoredox catalysis is also capable of promoting double decarboxylative coupling reactions between α,β-unsaturated acids 99 and N-(acyloxy)phthalimide derived 282 from aliphatic carboxylic acids to offer the corresponding alkylated styrene derivatives 283 in an efficient fashion (Scheme 99). [113][114][115][116] The reactions are known to proceed in the presence of a transition metal catalyst, such as ruthenium, copper, iridium etc., or an organocatalyst, such as PPh 3 . The E/Z ratio of the alkylated alkene products however depends on the catalyst used.…”

Synthesis of fluorinated allylic alcoholsviaphotoinduced decarboxylative cross-coupling of α-fluoroacrylic acids and alcohols

“…8–11 In addition, our group has recently reported a series of methodologies to access monofluoroalkenes via decarboxylation of fluoroacrylic acids. 12…”

Copper-catalyzed direct monofluoroalkenylation of C(sp3)–H bondsviadecarboxylation of α-fluoroacrylic acids

“…Therefore, the development of a novel and low-cost methodology for the monofluoroalkenylation of inert C(sp 3 )–H bonds with excellent Z / E selectivity for trisubstituted monofluoroalkenes is highly desirable. Based on our previous work on the decarboxylation of α-fluoroacrylic acids to synthesize monofluoroalkenes, 16 here, we demonstrate a practical and efficient protocol for the monofluoroalkenylation of inert C(sp 3 )–H bonds through the copper-catalyzed decarboxylation of α-fluoroacrylic acids (Scheme 1d). A wide range of α-fluoroacrylic acids and C–H patterns were identified as suitable substrates for this transformation.…”