Difunctionalization of gem-Difluoroalkenes via Photoredox Catalysis: Synthesis of Diverse α,α-Difluoromethyl-β-alkoxysulfones

Abstract

Visible-light-promoted alkoxysulfonylation of gem-difluoroalkenes using sulfonyl chlorides and alcohols has been developed. The reaction exhibits a relatively broad substrate scope with excellent functional group compatibility. This synthesis method includes an atom transfer radical addition-like process. The products can be used as platform molecules for further modification.

External oxidant-free and selective thiofunctionalization of alkenes enabled by photoredox-neutral catalysis

“…3 In contrast, the photoredox 1,2-bis-heteroatom difunctionalization 4 has been far less studied, especially the S ,heteroatom introduction. 5 The vicinal S ,heteroatom-functional groups such as S , O - and S , N -groups are ubiquitous key structural motifs in natural products, pharmaceuticals and other biologically active molecules 6 (Scheme 1). Besides, the sulfenyl and heteroatom moieties such as hydroxyl, alkoxyl and amino groups are attractive functionalities in organic synthesis because of their easily available transformation into other functional groups.…”

Multicomponent Sulfonylation of Alkenes to Access β-Substituted Arylsulfones

“…12a Yield: 47.4 mg, 74%; yellow oil (eluent: petroleum ether/ethyl acetate = 3:1); 1 H NMR (400 MHz, CDCl 3 ) δ 7.71 (d, J = 8.4 Hz, 2H), 7.25 (d, J = 8.0 Hz, 2H), 7.08 (d, J = 8.4 Hz, 2H), 6.77 (d, J = 8.4 Hz, 2H), 4.61 (dd, J = 2.8 Hz, J = 9.6 Hz, 1H), 3.70 (s, 3H), 3.54 (dd, J = 9.6 Hz, J = 14.4 Hz, 1H), 3.17 (dd, J = 2.8 Hz, J = 14.4 Hz, 1H), 2.99 (s, 3H), 2.36 (s, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 159. 8,144.4,137.7,130.7,129.6,128.2,127.9,114.2,77.8,63.6,56.3,55.3,ethyl)sulfonyl)benzene (4ada). 12a 45.4 mg, 70%; yellow oil (eluent: petroleum ether/ethyl acetate = 3:1); 1 H NMR (400 MHz, CDCl 3 ) δ 7.11 (dd, J = 5.2 Hz, J = 8.8 Hz, 2H), 6.43−6.31 (m, 4H), 6.04 (d, J = 8.4 Hz, 2H), 3.88 (dd, J = 2.8 Hz, J = 9.6 Hz, 1H), 2.98 (s, 3H), 2.81 (dd, J = 9.6 Hz, J = 14.8 Hz, 1H), 2.46 (dd, J = 2.8 Hz, J = 14.8 Hz, 1H), 2.25 (s, 3H); 13 C{ 1 H} NMR (100 MHz, CDCl 3 ) δ 165.7 (d, J C−F = 254.2 Hz), 159.9, 136.7 (d, J C−F = 3.2 Hz), 131.0 (d, J C−F = 9.5 Hz), 130.3,127.9,116.2 (d,114.3,77.8,63.6,56.2,55.3; 19 F{ 1 H} NMR (471 MHz, CDCl 3 ) δ − 104.2.…”

Defluorinative C–C Bond-Forming Reaction of Trifluoromethyl Alkenes with gem-(Diborylalkyl)lithiums

“…Among the fluorine-containing compounds, gem -difluoroalkenes, which are carbonyl group isosteres, are intriguing structural motifs because of their prevalence in many bioactive molecules (Scheme a) . Furthermore, such motifs serve as versatile synthetic precursors for the synthesis of other fluorine-containing compounds . The Julia–Kocienski and Wittig reactions have traditionally been used to synthesize gem -difluoroalkenes, but these methods frequently involve highly reactive intermediates or harsh conditions, resulting in a limited substrate scope.…”