Ruthenium‐Catalyzed Synthesis of 1,2‐Diketones from Alkynes

Abstract

International audienc

Dual gold/photoredox-catalyzed C(sp)–H arylation of terminal alkynes with diazonium salts

“…As demonstrated by representative Sonogashira–Hagihara and Suzuki–Miyaura coupling reactions in Scheme 4 , these substrates can be readily functionalized further using palladium catalysis. 12 Overall, this two-step protocol is complementary to stepwise palladium-catalyzed coupling sequences, making use of readily-available aryldiazonium salts rather than dihalogenated aryl iodide precursors ( Scheme 4 ).…”

One‐Pot, Two‐Step Metal and Acid‐Free Synthesis of Trisubstituted Imidazole Derivatives via Oxidation of Internal Alkynes Using an Iodine/DMSO System

“…Next, the coupling reactions between benzaldehyde and various internal alkynes were examined. Unfortunately, 1‐phenyl‐1‐propyne and 2‐butyne resulted in no product formation, (Table , 3o‐3p ), which is probably due to the reduced nucleophilicity of these substrates . Thereafter, 1,2‐bis(4‐bromophenyl)acetylene reacted smoothly to successfully afford 4,5‐bis(4‐bromophenyl)‐2‐phenyl‐1 H ‐imidazole in a favorable yield of 60 % ( 3q ).…”

Gold‐Catalyzed Oxidation of Internal Alkynes into Benzils and its Application for One‐Pot Synthesis of Five‐, Six‐, and Seven‐Membered Azaheterocycles

“…1‐(4‐Acetylphenyl)‐2‐phenylethane‐1,2‐dione ( 2h ): yellow crystals (102 mg, 81 %); mp 77.0–78.0 °C (hexane/ethyl acetate); R f 0.30 (hexane/ethyl acetate, 4:1); 1 H NMR (400 MHz, CDCl 3 ) δ 8.06 (s, 4H, Ar), 7.97 (d, J = 7.2 Hz, 2H, Ar), 7.68 (t, J = 7.5 Hz, 1H, Ar), 7.53 (t, J = 7.8 Hz, 2H, Ar), 2.65 (s, 3H, Me); 13 C NMR (100 MHz, CDCl 3 ) δ 197.3, 193.9, 193.7, 141.5, 136.1, 135.3, 132.9, 130.2, 130.1, 129.3, 128.8, 27.1; HRMS (ESI): m/z [M + Na] + calcd. for C 16 H 12 NaO 3 + : 275.0679, found 275.0677.…”