Boron Trifluoride Etherate Induced Stille Cross-Coupling Reaction of Aryltriazenes with Tributyl(phenyl)stannane Catalyzed by Recyclable Pd/C Catalyst

Abstract

A novel and efficient Pd/C-catalyzed Stille cross-coupling reaction of aryltriazenes with tributyl(phenyl)stannane has been realized in the presence of 1 equiv of BF3•OEt2 under room temperature. The Pd/C catalyst could be re-used several times and still retained its high activity. The present protocol, utilizes simple and recyclable catalyst, readily available starting materials and mild reaction conditions, provides an attractive methodology to a diverse range of biaryl products in moderate to excellent yields.

Recent advances in the chemistry of aryltriazene

“…Classical metal-catalyzed cross-coupling approaches to biaryl moieties generally require aryl halides, giving rise to various halogen-containing by-products, which might cause severe environmental issues. Recently, a variety of Pd-catalysed cross-coupling reactions employing aryltriazenes 6 as arylation reagents have been gradually unlocked by the groups of Tamao, 7 Li 8 and Wang, 9 among others 6 c ,10 (Scheme 4). In these triazene-mediated transformations, aryl boronic acids 7 , trifluorosilanes 8 , aryl halides 12 , and arenes ( 10 and 13 ) were generally utilized as coupling partners.…”