51525-37-2Relevant academic research and scientific papers
Reactions of Oxasilacyclopropane. Generation of Silanediyl by Photo and Thermal Induced Cycloelimination
Ando, Wataru,Hamada, Yoshitaka,Sekiguchi, Akira
, p. 952 - 954 (1983)
Dimesitylsilanediyl was generated from photolysis and pyrolysis of the oxasilacyclopropane (1) via a 2 + 1> cycloelimination reaction.
Fast kinetics study of the reactions of transient silylenes with alcohols. Direct detection of silylene-alcohol complexes in solution
Leigh, William J.,Kostina, Svetlana S.,Bhattacharya, Adroha,Moiseev, Andrey G.
scheme or table, p. 662 - 670 (2010/05/15)
The kinetic behavior of dimethyl-, diphenyl-, and dimesitylsilylene in hexanes solution in the presence of methanol (MeOH), tert-butanol (t-BuOH), and the respective O-deuterated isotopomers has been studied, with the goal of elucidating a detailed mechanism for the formal O-H insertion reaction of transient silylenes with alcohols in solution. The data are in all cases consistent with a mechanism involving the intermediacy of the corresponding silylene-alcohol Lewis acid-base complexes, which have been detected directly for each of the SiMe2-ROL and SiPh2-ROL (L = H or D) systems that were studied. Complexation proceeds effectively irreversibly (Keq ≥ 2 x 105 M-1) and at close to the diffusion-controlled rate in these cases. In contrast, the kinetic and spectroscopic behavior observed for SiMeS2 in the presence of these alcohols indicates the SiMeS2-ROL complexes are involved as steady-state intermediates, formed reversibly and 10-100 times more slowly than is the case with SiMe2 and SiPh2. Product formation from the silylene-alcohol complexes is shown to proceed via catalytic proton transfer by a second molecule of alcohol, the rate of which exceeds that of unimolecular intracomplex H-migration in all cases, even at submillimolar alcohol concentrations. The catalytic rate constants range from 109 to 1010 M-1 s-1 for the SiMe2-ROH and SiPh2-ROH complexes, sufficiently fast that the isotope effect ranges from ca. 2.5 to close to unity for all but the SiPh2-t-BuOL complex, where it is remarkably large (kHH/kDD = 10.8 ± 2.4). The value is consistent with a mechanism for catalysis involving double proton transfer within a cyclic five-membered transition state. The isotope effects on the ratio of the rate constants for catalytic proton transfer and dissociation of the SiMeS2-MeOH and SiMeS2-t-BuOH complexes suggest that a different mechanism for catalytic proton transfer is involved in the case of the sterically hindered diarylsilylene.
PHOTOLYSIS OF ORGANOPOLYSILANES. THE SYNTHESIS AND REACTIONS OF STABLE SILACYCLOPROPENES
Ishikawa, Mitsuo,Nishimura, Kunio,Sugisawa, Hiroshi,Kumada, Makoto
, p. 147 - 158 (2007/10/02)
Two stable silacyclopropenes, 1,1-dimensityl-2,3-bis(trimethylsilyl)-1-silacyclopropene and 1,1-dimesityl-2-phenyl-3-trimethylsilyl-1-silacyclopropene, have been prepared by photolysis of 1,1-dimesityl-1-trimethylsilylethynyltrimethyldisilane and 1,1-dimesityl-1-phenylethynyldisilane, respectively.It has been found that these silacyclopropenes are not affected by atmospheric oxygen, moisture and alcohols at room temperature. 1-Mesityl-1-methyl-2-phenyl-3-trimethylsilyl-1-silacyclopropene prepared by the photolyisis of 1-mesityl-1-phenylethynyltetramethyldisilane is rather stable toward atmospheric oxygen, but reacts readily with methanol in benzene to give a ring-opening methoxysilane.Photochemical and thermal behavior of these silacyclopropenes has been investigated.
