ChemInform Abstract: UNTERSUCHUNGEN IN DER SILACYCLOPENTADIENREIHE, DARST. UND EIGENSCHAFTEN VON DERIVATEN DES DIPHENYLSILACYCLOPENTADIENS

Abstract

Dimerisierung von Styrol (I) in Gegenwart von Lithium bei Anwesenheit von Dialkyldichlorsilanen (II) liefert die Diphenyl‐silacyclopentane (III), die durch Behandlung mit N‐Bromsuccinimid und nachfolgend Kaliumacetat in Acetonitril in die 2,5‐Diphenyl‐silacyclopentadiene (IV) übergeführt werden können.

Group 14 metalloles. 1. Synthesis, organic chemistry, and physicochemical data

“…94,97'192 1.1-Dimethyl-DPSI (60) crystallizes in the orthorhombic Pmn21 space group, Z = 2, with cell constants a = 15.669 A, b = 7.500 A, and c = 6.548 A.189 Molecules of 60 possess exact Cs symmetry; the mirror plane passes through the silicon atom and is normal to the plane of the silole ring. The carbon-carbon bond lengths within this ring (Table 14) are similar to those in cyclopentadiene and rather different from those found in thiophene (66) and 1,2,5-triphenylphosphole (68). The bond lengths are 1.466 and 1.345 A for C-C and C=C bonds, respectively.…”

“…section I.2.b) makes this compound reactive toward 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ). 66 The dehydrogenation can be achieved either at room temperature (2 days) or in refluxing benzene (16 h) with a high yield (86%) (eq 20). (b) Dehydrohalogenation.…”