Microwave‐Promoted Copper‐Free Sonogashira–Hagihara Couplings of Aryl Imidazolylsulfonates in Water
Aryl imidazol‐1‐ylsulfonates have been efficiently cross‐coupled with aryl‐, alkyl‐, and silylacetylenes in neat water under copper‐free conditions at 110 °C assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2‐dicyclohexylphosphino‐2′,6′‐dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA) as base, a wide array of disubstituted alkynes has been prepared in good to high yields in only 30 min.
Document Type: Research Article
Affiliations: Departamento de Química Orgánica and Instituto de Síntesis Orgánica (ISO), Facultad de Ciencias, Universidad de Alicante, Apartado 99, 03080 Alicante, Spain, Fax: (+34)-96-590-3549
Publication date: 2013-01-14