Bis(2,4,6-triisopropylphenyl)(fluorenylidene)stannene-diethyl ether (1a), a new stable compound with a formal tin-carbon double bond, has been synthesized by dehydrofluorination of the corresponding fluoro-stannane with tert-butyllithium; it has been characterized by NMR (delta(Sn-119) + 288 ppm, delta(C-13) + 133.85 ppm) and UV spectroscopy (lambda(max) 542 nm) and by electrophilic addition reactions to the tin-carbon unsaturation,
A Nearly Planar Stannene with a Reactive Tin–Carbon Double Bond
作者:Abdoul Fatah、Rami El Ayoubi、Heinz Gornitzka、Henri Ranaivonjatovo、Jean Escudié
DOI:10.1002/ejic.200701277
日期:2008.4
7-di-tert-butylfluorenylidenestannane, Tip2Sn=CR2, an isolable stannene that displays a deep-purple colour, was synthesized by dehydrofluorination of the corresponding fluorostannane by tert-butyllithium. It exhibits the shortest Sn=C distance [2.003(5) A] and the slightest twisting around this unsaturation (10°) among the known stannenes. Its reaction with benzaldehyde according to a [2+2] cycloaddition
The synthesis, isolation, spectroscopic characterization (IR, multi-nuclear NMR) and single-crystal X-ray diffraction analysis of FSi(PH2)3 (1a), the first isolable fluorophosphanylsilane, is reported along with the gas phase decomposition of 1a, MeSi(PH2)3 (1b) and EtSi(PH2)3 (1c) under flash vacuum or pulsed pyrolysis conditions and matrix isolation of the products. The title compound is formed quantitatively
Fluoro-, chloro- and bromostannylphosphines (8-10) complexed on phosphorus by tungsten pentacarbonyl have been synthesized by reaction between lithium mesityl(tungsten pentacarbonyl)phosphide 4 and the corresponding dihalo(diisityl)tin (isityl: 2,4,6-triisopropylphenyl). Reaction of 8 with tert-butyllithium afforded the stable lithium fluorostannylphosphide 11. Addition of Me3SiCl or MgBr2 to 11 gave the corresponding chloro- and bromoderivatives 14 and 15. Similar compounds 16 and 17 were obtained from 9 and 10 and DBU. 11, 14, 15, 16 and 17 present a large (1)J(SnP) coupling constant (2099.0 to 2151.4 Hz) indicating a partial Sn-P double bond.
The first three-membered ring compound containing two tin and one carbon atoms, 1,1,2,2-tetra(2,4,6-triisopropylphenyl)-3-fluorenylidene-1,2-distannirane, has been synthesized in a two-step procedure from the 9-[bis(2,4,6-triisopropylphenyl)fluorostannyl]chloromethylenefluorene.
First characterization of a compound with a tin–germanium double bond: the dimesityl(diisitylstanna)germene (Is)<sub>2</sub>SnGe(Mes)<sub>2</sub>
The dimesityl(diisitylstanna)germene 4 [isityl (Is) = 2,4,6-triisopropylphenyl] is synthesized by dehydrofluorination of the corresponding (fluorostannyl)germane 1 by tert-butyl-lithium at low temperature; its structure is evidenced at -20 degrees C by Sn-119 NMR spectroscopy (delta + 360), by addition of water and methanol to the tin-germanium double bond and by a [2 + 2] cycloaddition with benzaldehyde; warming the stannagermene 4 to room temperature affords the dimesityl(tetraisityldistanna)germirane 8.