Palladium/Copper Dual Catalysis for the Cross‐Coupling of Aryl(trialkyl)silanes with Aryl Bromides

Abstract

Whereas aryl(trialkyl)silanes are considered to be ideal organometallic reagents for cross-coupling reactions owingt ot heir stability,l ow toxicity,s olubility,a nd easy accessibility,t hey are generally inert under typical crosscoupling conditions.D isclosed herein is ap alladium/copper catalytic system that enables the cross-coupling of trimethyl, triethyl, tert-butyldimethyl, and triisopropyl aryl silanes with aryl bromides.This process is applicable to the sequential C À H and CÀSi bond arylation of thiophenes and the synthesis of poly(thiophene-fluorene)s.

Designing Cross‐Coupling Reactions using Aryl(trialkyl)silanes

“…As ar esult,t he palladium/copper(II) catalysts ystem was effectivef or the cross-coupling of aryl(trialkyl)silanes with aryl bromides and provided av ariety of biaryl products. [39] For example,2 -triethylsilylbenzo[b]thiophene reacted smoothly with p-anisylb romide in the presence of Pd 2 (dba) 3 ,T TMPP [tris (2,4,6-trimethoxyphenyl)phosphine],C uF 2 ,a nd as toichiometric amounto fC sF in DMI (Scheme 15). This reactionc ould also be used with varioust rialkylsilyl groups such as trimethylsilyl, tert-butyldimethylsilyl,and even bulky triisopropylsilyl.…”