69322-38-9Relevant academic research and scientific papers
On the Problem of the Intermediate Formation of Silanone R2Si=O by Reactions of Silenes with Dinitrogen Oxide
Wiberg, Nils,Preiner, Gerhard,Schurz, Klaus
, p. 1407 - 1412 (2007/10/02)
The silaethene Me2Si=C(SiMe3)2 (1a; unstable; from 1a * Ph2C=MSiMe3 = 4) forms with N2O an unstable cycloadduct, which decomposes under isomerization or cleavage.It was not possible to decide clearly, whether the last reaction, which leads to (Me3Si)2CN2 and polymers with (Me2SiO)n groups, proceeds with intermediate formation of silanone Me2Si=O or not (no trapping product with Et3SiH, but with Me3SiCl).The silanimines Me2Si=NSitBu3 (2a; unstable; from 2a * tBu3SiN3 = 7) and tBu2Si=NSitBu3 (2b; metastable) form with N2O unstable cycloadducts, which, under participation of the silanimines, react into products (10) being composed of a molecular silanone and a molecule silanimine.As has been shown by trapping experiments with Et3SiH, Me3SiCl, or Me3SiOMe, latter reaction involves unstable free silanones Me2Si=O (3a) or tBuSi=O (3b) as intermediates. 3b, generated in benzene from 2b/NO2 in the presence of equimolar amounts of tetrahydrofuran (THF), obviously forms an adduct 3b*THF, which is trapped by excess 2b.When 3b is produced in THF as solvent, the silanone starts THF polymerization, indicating a high Lewis acidity of silanones.
Adduct Formation and Reactivity of Silane- and Germaneimines Me2E=NR (E = Si, Ge)
Wiberg, Nils,Preiner, Gerhard,Karampatses, Petros,Kim, Chung-Kyun,Schurz, Klaus
, p. 1357 - 1368 (2007/10/02)
Silane- and Germaneimines Me2E=NR (E = Si, Ge; R = silyl), generated as reactive intermediates by thermal cycloreversion from cycloadducts of Me2E=C(SiMe3)2 or Me2E=NR with silyl azides RN3, combine with reactants a (e.g.NEtMe2) under addition (formation of adducts 7), with a-b under insertion into the a-b bond (formation 13-16), with a=b (e.g.RN=EMe2, O=CPh2) under cycloaddition (e.g. formation of 17, 18), with a=b=c (e.g.R'N=N=N) under cycloaddition (e.g. formation of 19, 20), and with a=b-c-H (e.g.CH2=CR-CH2-H, O=CMe-CH2-H) under ene reaction (formation of 21-24). cycloaddition of Me2Si=NR with organic 1,3-dienes (e.g.CH2=CR-CR=CH2, cyclopentadiene) is not observed.By comparison with ethenes Me2E=C(SiMe3)2, imines Me2E=NR have greater tendency for insertion and lesser tendency for cycloaddition; by comparison with silaneimines Me2Si=NR, germaneimines Me2Ge=NR are possibly less Lewis acidic.
