Palladium-Catalyzed Suzuki Couplings of 2,3-Dibromonorbornadiene: Synthesis of Symmetrical and Unsymmetrical Aryl-Substituted Norbornadienes
Journal
European Journal of Organic Chemistry
Date Issued
2005
Author(s)
Abstract
Abstract Palladium‐catalyzed Suzuki coupling reactions between 2,3‐dibromonorbornadiene and arylboronic acids were investigated. These reactions provide an efficient method for the synthesis of symmetrical 2,3‐diarylnorbornadienes which are not accessible using the traditional Diels–Alder cycloaddition reactions. The optimized reaction conditions of the Suzuki coupling reactions were found using [Pd 2 (dba) 3 ] (0.5 mol%), t Bu 3 P (1.4 mol%) and CsF in THF. High yields of the Suzuki coupling products were obtained when electron‐rich arylboronic acids were used. On the other hand, Suzuki coupling reactions with electronic‐deficient or sterically hindered arylboronic acids gave lower yields of the corresponding 2,3‐di‐arylnorbornadienes. Unsymmetrical mono‐ and diaryl‐substituted norbornadienes were also prepared in good yields using this method. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Type
journal article