Tetrahedron

Practical synthesis of pinacolborane for one-pot synthesis of unsymmetrical biaryls via aromatic C–H borylation–cross-coupling sequence

…, J Umeda, Y Yamamoto, T Ishiyama, N Miyaura

Index: Kikuchi, Takao; Nobuta, Yusuke; Umeda, Junko; Yamamoto, Yasunori; Ishiyama, Tatsuo; Miyaura, Norio Tetrahedron, 2008 , vol. 64, # 22 p. 4967 - 4971

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Citation Number: 36

Abstract

A method for practical preparation of pinacolborane from borane-diethylaniline and pinacol was newly developed. Aromatic C–H borylation of arenes with pinacolborane or bis (pinacolato) diboron catalyzed by 1/2 [Ir (OMe)(COD)] 2-(4, 4′-di-tert-butyl-2, 2′- bipyridine) at 25° C in hexane to give arylboronic esters was directly followed by cross- coupling with aromatic bromides at 60° C in the presence of PdCl2 (dppf)(3.0 mol%) and ...