The First Stable Derivative of 7‐Stannanorbornane and Its Thermolysis

Abstract

Free dimethylstannanediyl (“dimethylstannylene”) (2)—to be regarded as truly free because of its synthesis—has been generated by thermolysis of the adduct (1) which is stable at −30°C. A concerted mechanism is proposed to account for the formation of (2).

Fluoride-ion-induced rearrangements of chloromethyl-substituted silanes

“…In each we observe reaction resulting in the production of two fluorosilanes obtained by the migration of an R or methyl group to the chloromethyl moiety with loss of chloride. In all of these com- Me2RSiCH2Cl R = Me3SiCH2 (7) a large number of products; these were not characterized R = Me3SiO (8) no reaction with KF; many products with CsF R = CH2C1 (9) yields Me2SiF, and CH2=CH, Me3SiX X = CH2CH2CH2C1 (10) no reaction with KF or CsF X = CHC12 (11) yields Me3SiF and CH2C12 X = CHC1CH3 (12) no reaction with KF or CsF "All results were determined by GC and GC-MS. pounds except Me3SiCH2Cl there is a competition between two potential migrating groups (eq 1). Our earlier report1 Me2RSiCH,Cl---Me2(RCH2)SiF + MeREtSiF " 18-crown-6 (i) suggested that the major factor controlling migration was the ability of the migrating group to support the negative charge generated in the transition state.…”

“…Other factors like steric hindrance (12) or the difficulty of rearrangement to other than an adjacent position ( 10) lead to no reaction. Finally, the case where R = Me3SiO in Me2RSiCH2Cl (8) suggests that the strength of the bond between Si and R, in this case an Si-0 bond, may control reactivity. There seems to be a delicate balance here, for with KF there is no reaction, but with CsF a very complex reaction mixture is obtained.…”

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

“…Instead, the aromatic hydrocarbon and products apparently resulting from a transient stannylene were isolated. 139,142 The relative instability of stanna(and germa)norbornadienes has been attributed to the larger size of the heteroatom, which sufficiently distorts the ring system to the point where elimination of stannylene (or germylene) readily occurs. 32 (c) Photochemical Decomposition of Metallanorbornadienes.…”

3,3-Di-tert-butyl-N,4,5,6,7-pentaphenyl-1,2-dihydro-1,2,3-diazastannepine-1,2-dicarboximide monohydrate, C44H43N3O2Sn.H2O

“…498 K without decomposition), however, could not be explained in comparison with similar compounds such as the dimethyl-and diisopropylstanna analogues which decompose instantaneously with the elimination of the dialkylstannylene. Only the stanna-8,9,10-trinorbornene resulting from tetracyanoethylene and the 1,1-dimethyl-2,3,4,5-tetraphenylstannole can be isolated at 243 K (Grugel, Neumann & Schriewer, 1979). IR and mass spectrometry did not give clear information about the structure of the title compound.…”