Bis(pyrazolyl)methane Copper Complexes as Robust and Efficient Catalysts for Sonogashira Couplings. Issue 34 (29th October 2015)

• Record Type: Journal Article
• Authors: Moegling, Julian; Benischke, Andreas D.; Hammann, Jeffrey M.; Vepřek, Nynke A.; Zoller, Florian; Rendenbach, Bettina; Hoffmann, Alexander; Sievers, Holger; Schuster, Michael; Knochel, Paul; Herres‐Pawlis, Sonja
• Is Part Of: European journal of organic chemistry. Issue 34(2015)
• Page Start: 7475
• Page End: 7483
• Publication Date: 2015-10-29
• Subjects: Homogeneous catalysis -- Cross‐coupling -- C–C coupling -- Copper -- ­Alkynes -- N ligands; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201501117
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: A series of bis(pyrazolyl)methane copper complexes were found to catalyze a fast palladium‐free Sonogashira coupling reaction of several iodoarenes with terminal alkynes such as phenylacetylene, propargyl benzyl ether, and ( tert ‐butyl‐dimethyl)silylacetylene. These reactions proceed with CuCl2 · 2H2 O (10 mol‐%) under aerobic conditions and the corresponding chelate ligand (10 mol‐%), with its tailored facial coordination mode, is crucial for the success of the reaction. The coupling can also be carried out in water with liquid aryl halides and a phase‐transfer catalyst. Abstract : A series of bis(pyrazolyl)methane copper complexes were found to catalyze a fast palladium‐free Sonogashira coupling reaction of various iodoarenes with terminal alkynes. The reactions proceed under aerobic conditions, which makes this system synthetically highly useful. For liquid electrophiles, a substitution of DMF with water is possible when a phase‐transfer catalyst is provided.