Synthesis of extended α,α′-oligo(silylthiophenes) by cerium(iv) oxidative coupling reactions
作者:Ali H. Mustafa、Michael K. Shepherd
DOI:10.1039/a806600k
日期:——
Cerium(IV) oxidative dimerisations of 4,4â²-bis(trimethylsilyl)-2,2â²:5â²,2â²â²-terthiophene and the quaterthienyl analogue 1c gave the corresponding sexi- and octi-thiophenes; the latter have been used to prepare α-linked hexadecithiophene and tetracosithiophene derivatives.
Based upon a twofold bromine-lithium exchange with 2,5-dibromo thiophene and sequential trapping of the dilithio intermediate, organo zinc halides were generated in situ and subsequently transformed by Negishi cross-coupling to unsymmetrically substituted thiophenes in a one-pot fashion. Application of this novel sequence to diiodo(hetero)arenes quickly furnishes highly interesting building blocks for materials science applications.