66239-85-8Relevant academic research and scientific papers
Storing of the Labile Silaethene Me2Si=C(SiMe3)2 with Benzophenone
Wiberg, Nils,Preiner, Gerhard,Schurz, Klaus,Fischer, Gerd
, p. 1468 - 1474 (2007/10/02)
Benzophenone Ph2C=O is able to "store" the silaethene Me2Si=C(SiMe3)2 (1), produced from Me2SiX-CLi(SiMe3)2 (X = F, Br, Ph2PO4), under formation of a cycloadduct (2b).At about 100 deg C, 2b by way of 1 transfers into the cycloadduct of 1 and Ph2C=O (3b), which in the course of transformation decomposes visibly (in the absence of Me3SiCl) or only by traces (in the presence of Me3SiCl) to secondary products.In the presence of ROH (R = H, Me, tBu, MeCO) or PhN=NSiMe3 or RN3 (R = tBu, Me3Si) or 2,3-dimethylbutadiene (dmb) about 100 deg C 2b and 3b form by way of 1 insertion products of 1 into the OH bond of ROH or a cycloadduct of 1 and PhN=NSiMe3 or cycloadducts of 1 and RN3 or cycloadduct and an ene reaction product of 1 and dmb.The rate constants/half lives of the first order transformation of 2b into 3b or of the first order decomposition of 2b or of 3b in the presence of reactive traps for 1 (ROH, Me3SiN3; benzene as solvent) are in the order of 0.3E-4 s-1/τ1/2 = 7 h (2b --> 3b; 90 deg C) 3E-4 s-1/τ1/2 = 3/4 h (2b + traps; 90 deg C), 0.4E-4 s-1/τ1/2 = 5 h (3b + traps, 110 deg C). - Keywords: Silaethene Me2Si=C(SiMe3)2, Insertions, Cycloadditions, Kinetic Studies
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.
