Investigation of the catalytic activity of a Pd/biphenyl-based phosphine system in the Ullmann homocoupling of aryl bromides

…, E Azadi, A Ataei, M Joshaghani, E Rafiee

Index: Nadri, Shirin; Azadi, Ehsan; Ataei, Ali; Joshaghani, Mohammad; Rafiee, Ezzat Journal of Organometallic Chemistry, 2011 , vol. 696, # 18 p. 2966 - 2970

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Citation Number: 20

Abstract

We described Ullmann homocoupling promoted by a Pd/biphenyl-based phosphine system using DMF as solvent. Using Hammett equation it is found that the rate determining step of the reaction depends on the electronic nature of substituents of aryl bromides. Increase the rate of reaction with decreasing the electron donating of the substituent from NH2 to H suggesting an oxidative addition step as the rate determining step. Decrease the rate of ...