2372-29-4Relevant academic research and scientific papers
Interconversion and reactivity of manganese silyl, silylene, and silene complexes
Price, Jeffrey S.,Emslie, David J. H.
, p. 10853 - 10869 (2019/12/23)
Manganese disilyl hydride complexes [(dmpe)2MnH(SiH2R)2] (4Ph: R = Ph, 4Bu: R = nBu) reacted with ethylene to form silene hydride complexes [(dmpe)2MnH(RHSiCHMe)] (6Ph,H: R = Ph, 6Bu,H: R = nBu). Compounds 6R,H reacted with a second equivalent of ethylene to generate [(dmpe)2MnH(REtSiCHMe)] (6Ph,Et: R = Ph, 6Bu,Et: R = nBu), resulting from apparent ethylene insertion into the silene Si-H bond. Furthermore, in the absence of ethylene, silene complex 6Bu,H slowly isomerized to the silylene hydride complex [(dmpe)2MnH(SiEtnBu)] (3Bu,Et). Reactions of 4R with ethylene likely proceed via low-coordinate silyl {[(dmpe)2Mn(SiH2R)] (2Ph: R = Ph, 2Bu: R = nBu)} or silylene hydride {[(dmpe)2MnH(SiHR)] (3Ph,H: R = Ph, 3Bu,H: R = nBu)} intermediates accessed from 4R by H3SiR elimination. DFT calculations and high temperature NMR spectra support the accessibility of these intermediates, and reactions of 4R with isonitriles or N-heterocyclic carbenes yielded the silyl isonitrile complexes [(dmpe)2Mn(SiH2R)(CNR′)] (7a-d: R = Ph or nBu; R′ = o-xylyl or tBu), and NHC-stabilized silylene hydride complexes [(dmpe)2MnH{SiHR(NHC)}] (8a-d: R = Ph or nBu; NHC = 1,3-diisopropylimidazolin-2-ylidene or 1,3,4,5-Tetramethyl-4-imidazolin-2-ylidene), respectively, all of which were crystallographically characterized. Silyl, silylene and silene complexes in this work were accessed via reactions of [(dmpe)2MnH(C2H4)] (1) with hydrosilanes, in some cases followed by ethylene. Therefore, ethylene (C2H4 and C2D4) hydrosilylation was investigated using [(dmpe)2MnH(C2H4)] (1) as a pre-catalyst, resulting in stepwise conversion of primary to secondary to tertiary hydrosilanes. Various catalytically active manganese-containing species were observed during catalysis, including silylene and silene complexes, and a catalytic cycle is proposed.
THERMAL ISOMERIZATION AND DECOMPOSITION OF 3,3-DIETHYL-2,4-DIMETHYL-3-SILATHIETANE
Gusel'nikov, L. E.,Sokolova, V. M.,Vonina, E. A.,Zalikin, V. G.,Nametkin, N. S.,et al.
, p. 145 - 154 (2007/10/02)
Pyrolisis of 3,3-diethyl-2,4-dimethyl-3-silathietane (I) has been studied at temperatures from 300 to 530 deg C using the pulse pyolytic GC-MS method.Decomposition of I proceeds with the elimination of ethane, ethylene, propylene, butadiene, cis- and trans-but-2-ene, and also with the loss of atomic sulphur.Isomerization into sulphur-containing unsaturated compounds is the main transformation process of I.The intermediacy of 1,1-diethyl-2-methyl-1-silaethylene and diethylsilathione is also discussed.
