External oxidant-free cross-coupling of arylcopper and alkynylcopper reagents leading to arylalkyne

Abstract

External oxidant-free cross-coupling of arylcopper and alkynylcopper reagents for the formation of arylalkynes was performed.

Sterically Demanding Novel Triazole Based Tertiary Phosphines: Synthesis, Transition Metal Chemistry and Catalytic Applications

“…The azide formation was confirmed by FT‐IR which showed a characteristic stretching frequency of the azide moiety at 2127 cm −1 and mass spectrometry showed a molecular ion peak [M+K] + at 504.1835. The bulky azide 1 on treatment with copper(I) phenylacetylide [44] in the presence of triazole‐ a NHC ( a NHC=abnormal N‐heterocyclic carbene) [45] in 1,2‐dichloroethane yielded copper(I)‐1,2,3‐triazolide intermediate, which on further treatment with elemental iodine afforded compound 2 in good yield (Scheme 1). The 1 H NMR spectrum of 2 showed a singlet at 2.33 ppm due to methyl protons and aromatic protons appeared as multiplets in the range of 6.93–7.99 ppm, while the CH protons of Ph 2 CH groups resonated at 5.07 ppm.…”

Copper‐Catalyzed Carboxylation of Aryl Thianthrenium Salts with CO2

“…CuH decomposes to release H 2 along with the generating of active Cu 0 species [18] . To further verify the carboxylation step of aryl copper(I) in this system, phenyl copper(I) was prepared [19] and reacted with 1 atm CO 2 in the presence of L12 at room temperature (Scheme 3d). The desired product benzoic acid was obtained in 83 % yield, indicating that arylcopper(I) may serve as the key intermediate to perform CO 2 insertion [20] …”

“…When reducing the loading of L16 to 10 %, the reaction proceeded smoothly, but the yield of 2 a was reduced to 67 % (Table 2, entry 18). In addition, control experiments revealed that both the copper catalyst and ZnEt 2 were essential to this transformation (Table 2, entries [19][20]. So we selected the conditions mentioned in entry 16 as the standard reaction conditions.…”

Synthesis of (Deoxy)difluoromethylated Phosphines by Reaction of R2P(O)H with TMSCF3 and Their Application in Cu(I) Clusters in Sonogashira Coupling

“…24 The compound was obtained as a white solid: 50:1 PE/EA as the eluent; 109.9 mg, 99% yield; 1 1-Methoxy-3-(p-tolylethynyl)benzene (9d). 32 The compound was obtained as a yellow solid: 50:1 PE/EA as the eluent; 104.3 mg, 94% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 7.42 (d, J = 7.8 Hz, 2H), 7.21 (t, J = 7.9 Hz, 1H), 7.12 (d, J = 7.7 Hz, 3H), 7.05 (s, 1H), 6.86 (d, J = 8.3 Hz, 1H), 3.77 (s, 3H), 2.33 (s, 3H); 13 1-Methoxy-2-(p-tolylethynyl)benzene (9e). 33 The compound was obtained as a yellow oil: 50:1 PE/EA as the eluent; 103.2 mg, 93% yield; 1 H NMR (400 MHz, CDCl 3 ) δ 7.46 (dd, J = 13.7, 7.7 Hz, 3H), 7.26 (t, J = 7.9 Hz, 1H), 7.12 (d, J = 7.8 Hz, 2H), 6.95−6.83 (m, 2H), 3.87 (s, 3H), 2.33 (s, 3H); 13 3-(p-Tolylethynyl)pyridine (9f).…”