21711-52-4Relevant articles and documents
A highly efficient catalytic system for microwave-assisted Suzuki-Miyaura reactions as well as room temperature homocoupling reactions of arylboronic acids in aqueous media
Tairai, Archana,Sarmah, Chandan,Das, Pankaj
experimental part, p. 843 - 848 (2012/08/14)
An in situ generated catalytic system derived from PdCl2 and (C6H5)3CNH2 shows good-to-excellent activity (upto 92% isolated yield) in the microwave-assisted Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in aqueous media. Both electron-donating and electron-withdrawing aryl bromides can be efficiently coupled with arylboronic acids. Chloroarenes can also be coupled, but much lower yields are obtained. Interestingly, the same catalytic system is also found to be effective for homocoupling reactions of arylboronic acids in water. Moderate-to-excellent yields of symmetrical biphenyl compounds can be achieved at room temperature.
Synthetically Useful Aryl-Aryl Bond Formation via Grignard Generation and Trapping of Arynes. A One Step Synthesis of p-Terphenyl and Unsymmetric Biaryls
Hart, Harold,Harada, Katsumasa,Du, Chi-Jen Frank
, p. 3104 - 3110 (2007/10/02)
A one-pot route to p-terphenyls is described.Addition of 1,4-dibromo-2,5-diiodobenzene, 1, to excess aryl Grignard reagent gives the terphenyl di-Grignard 2 and the trihalo mono-Grignard 5.After aqueous quench, p-terphenyls are isolated in 30percent to 50percent yield (Table I).This yield can be improved to 70-80percent by adding potassium tert-butoxide or lithium tetramethylpiperidide to the reaction mixture prior to workup.Mechanisms involving organometallic aryne intermediates are proposed.With o-bromoiodoarenes in place of tetrahaloarenes the method can be adapted to prepare unsymmetric biaryls in good yield (Table II).
