Thiophenes germanium-substituted

Another germanium-based hnker has been developed for solid-phase synthesis of a pyrazole hbrary [79]. A new iterative synthesis of regioregular oligothiophenes has been developed in which double-couphng after each iteration minimizes deletion sequences. The method exploits the susceptibility of a-silyl- but not a-ger-myl-substituted thiophene derivatives towards nucleophilic ipso protodemetalation and features an unusual base-free Suzuki-type coupling product. The strategy... 

The reaction of germanium and tin chloride allowed the formation of similar germyl and stannyl thiophene [6]. Regio-selective silylation was also achieved in the case of the substituted thiophene ring. The selective attachment of a trimethylsilyl group at the 2- or 5-positions of 3-alkylthiophene was obtained as shown in Scheme 14.4 [13]. 

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