Reversible Stannylenoid Formation from the Corresponding Stannylene and Cesium Fluoride
Chenting Yan1, Zhifang Li1, Xu-Qiong Xiao1
1Hangzhou Normal University, Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, No. 58 Haishu Rd. Hangzhou, 311121, Zhejiang, China.
Abstract:
A fluorostannylenoid (Cs+ [R2 SnF]- (9), R2 =(TMS)2 CCH2 CH2 C(TMS)2 ) was prepared by reacting a stable dialkylstannylene (R2 Sn (8), R2 =(TMS)2 CCH2 CH2 C(TMS)2 ) with cesium fluoride at room temperature in THF. While 9 is stable in THF and DME, removal of the solvent leads to the regeneration of stannylene 8. No reaction occurred when 8 was treated with CsF in a hydrocarbon solvent. Addition of dibenzo-21-crown-7 ether to the THF solution of stannylenoid 9 followed by usual workup affords the corresponding crystalline stannylenoid crown ether complex, the X-ray structural analysis of which revealed a fluorine-bridged contact ion-pair structure. The reaction of 9 with excess phenylacetylene gives the corresponding di(phenylethynyl)stannane.
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