One-pot synthesis of 1,3-enynes with a CF₃ group on the terminal sp² carbon by an oxidative Sonogashira cross-coupling reaction

Abstract

Oxidative Sonogashira cross-coupling reactions of (E)-trimethyl(3,3,3-trifluoroprop-1-enyl)silane with arylacetylene were achieved using silver fluoride and a palladium catalyst, to afford high yields of various 1,3-enynes with a CF3 group on the terminal sp(2) carbon. Silver fluoride promoted C-Si bond dissociation and oxidation of palladium, enabling catalytic use of palladium.

Polycyclic aromatic hydrocarbon-substituted push–pull chromophores: an investigation of optoelectronic and nonlinear optical properties using experimental and theoretical approaches

“…Compound 6: colorless oil; 202 mg, 90%; CC: (SiO 2 ; c-hexane); R f = 0.40 (SiO 2 ; c-hexane); 1 H NMR (400 MHz, CDCl 3 , 298 K): δ = 0.33 (s, 9 H), 7.41 (t, J = 7.7 Hz, 1 H), 7.52 (t, J = 7.5 Hz, 1 H), 7.58 (t, J = 7.6 Hz, 1 H), 7.70 (d, J = 7.1 Hz, 1 H), 7.83 (t, J = 7.5 Hz, 2 H), 8.33 ppm (d, J = 8.2 Hz, 1 H);13 C NMR (100 MHz, CDCl 3 , 298 K): δ = 133.5, 133.2, 131.0, 129.1, 128.4, 127.0, 126.5, 126.3, 125.3, 120.9, 103.2, 99.6, 0.26 ppm. Spectral data was consistent with literature[38].…”

“…All reagents were purchased as reagent grade and used without further purification. Compounds 2 [37], 3 [37], 6 [38], 7 [38], 10 [39], and 11 [39] were prepared according to literature procedures. Solvents for extraction or column chromatography were distilled before usage.…”

Cu(I)‐Catalyzed Enantioselective γ‐Boryl Substitution of Trifluoromethyl‐ and Silyl‐Substituted Alkenes

“…The newly formed stereocenter in 6 has an S ‐configuration. We also performed an oxidative Sonogashira cross‐coupling reaction of ( S )‐ 4 a (Scheme 3B) [16,17] . This reaction allowed the synthesis of chiral 1,3‐enynes bearing a gem ‐difluoromethylene moiety [( S )‐ 7 ] (25 % 19 F NMR yield, 18 % isolated yield, 76 % ee, 100 % es).…”

Pd/Cu-Catalyzed Vinylation of Terminal Alkynes with (2-Bromoethyl)diphenylsulfonium Triflate

“…The conjugated carbon–carbon double and triple bonds of 1,3-enynes can be selectively or concurrently transformed, leading to the construction of very different chemical scaffolds such as aromatic systems, heterocycles, allenes, and 1,2- or 1,4-addition products . Because of their usefulness and interesting reactivity, significant efforts have been dedicated to develop efficient methods for the preparation of 1,3-enynes. − The known synthetic routes toward 1,3-enynes include Wittig or Horner-Wadsworth-Emmons (HWE) reactions, carbene-based cross-couplings, dehydrogenative couplings of 1-alkynes and alkenes, hydroalkynylations of allenes, hydrofunctionizations of 1,3-diynes, enzyme-catalyzed biosynthesis, decarboxylative homodimerization of propiolic acids, selective dimerizations of alkynes, alkynylations of alkenes or organometallic alkenes, and Sonogashira reactions (Scheme ). − Notably, the transition-metal-catalyzed Sonogashira couplings of terminal alkynes with alkenyl (pseudo)­halides have been considered as one class of the most convenient and straightforward strategies to afford 1,3-enyne moieties (Scheme b) .…”

“…Because of their usefulness and interesting reactivity, significant efforts have been dedicated to develop efficient methods for the preparation of 1,3-enynes. − The known synthetic routes toward 1,3-enynes include Wittig or Horner-Wadsworth-Emmons (HWE) reactions, carbene-based cross-couplings, dehydrogenative couplings of 1-alkynes and alkenes, hydroalkynylations of allenes, hydrofunctionizations of 1,3-diynes, enzyme-catalyzed biosynthesis, decarboxylative homodimerization of propiolic acids, selective dimerizations of alkynes, alkynylations of alkenes or organometallic alkenes, and Sonogashira reactions (Scheme ). − Notably, the transition-metal-catalyzed Sonogashira couplings of terminal alkynes with alkenyl (pseudo)­halides have been considered as one class of the most convenient and straightforward strategies to afford 1,3-enyne moieties (Scheme b) . Alkenyl chlorides, bromides, and iodides and dialkenyl chalcogenides as well as trimethyl­(3,3,3-trifluoroprop-1-enyl)­silane have been successfully used as the alkenyl sources in the reactions.…”