Reactions of [o-(Fluorodimethylsilyl)phenyl]lithium with GeCl₂ and SnCl₂: Preparation of Polyfunctionalized Four-Membered and Five-Membered Cyclic Linkages of Heavier Group 14 Elements

Abstract

Reactions of [o-(fluorodimethylsilyl)phenyl]lithium (1) with GeCl 2 and SnCl 2 produce benzosilagermacyclobutene 2 and benzosiladistannacyclopentene 3, respectively, both of which have o-(fluorodimethylsilyl)phenyl groups on the germanium and tin atoms. The molecular structures of 2 and 3 were determined by X-ray crystallographic analysis, which reveals the structural features of the functionalized four-and five-membered cyclic linkages of the heavior group 14 elements.

Synthesis, structure and reactions of triarylgermyl anion with α,δ-ambiphilic character

“…We have recently reported that the reaction of [o-(fluorodimethylsilyl)phenyl]lithium (1) as an a,g-ambiphilic species III (n = 1) with GeCl 2 produced benzosilagermacyclobutene 2 having two o-(fluorodimethylsilyl)phenyl groups on the germanium atom in the four-membered ring. 5 Compound 2 is expected to exhibit unique reactivity because of the highly strained four-membered ring and the highly electrophilic fluorosilyl functionality. Here we report that the reaction of 2 with KF leads to a ring-opening reaction to give a novel triarylgermyl anion 3 (a,d-ambiphilic species III (n = 2)), in which a germyl anion center and three electrophilic fluorosilyl groups are linked to each other through o-phenylene frameworks, and also that the reaction of 3 with a Lewis acid reversibly leads to a ring-closing reaction to regenerate 2.…”