作者:Hamid Shirani、Tomasz Janosik
DOI:10.1021/om8003114
日期:2008.8.1
A concise route to I-sila-, 1-germa-, and I-selenacyclohepta-2,4,6-trienes containing two fused benzo[b]thiophene units is described. Metalation of the ethylene acetal of 3-bromobenzo[b]thiophene2-carboxaldehyde and subsequent quenching with Me2SiCI2, Me2GeCI2, or (PhS02)2Se gave the corresponding bis(benzo[b]thiophen-3-yl)silane, -germane, or -selenide, respectively, which were subjected to deprotection, followed by McMurry coupling, eventually affording the target compounds in good overall yields. It was also concluded that application of this approach to synthesis of related benzo-fused metallacyclohepta-2,4,6-trienes is limited to electron-deficient targets, as attempts involving electronrich substrates faile d or gave only low yields at the final McMurry coupling stage.