87710-79-0Relevant academic research and scientific papers
Reactions of coordinated organosilanes: cobalt carbonyl complexes of ethynylhydrogenosilanes
Corriu, Robert J. P.,Moereau, Joael J. E.,Praet, Herve
, p. C39 - C52 (1989)
Cobalt carbonyl complexes of mono-, di- and tri-ethynylsilanes containing silicon-hydrogen bonds are obtained by selective-coordination of the triple bond in ethynylhydrogenosilanes.The silicon-hydrogen bond of the coordinated ethynylsilanes reacts spontaneously with methanol, water, benzaldehyde and phenylacetylene.The silicon-hydrogen bonds in the ethynylsilane-cobalt carbonyl complexes show enhanced reactivity in hydrosilylation.
Selective synthesis of functional alkynylmono- and -trisilanes
Hoffmann, Florian,Wagler, Joerg,Roewer, Gerhard
experimental part, p. 1133 - 1142 (2010/06/20)
The selective synthesis of functional alkynylsllanes RC=C(SiMe 2)m,-X (m = 1, 3) was investigated. Monofunctionalization with or without protecting groups gave moderate to good yields of alkynyldimethylmonosilanes RC=CMe2SiX [R = Ph, X = Cl. (1), NEt 2 (2), OMe (3), H (4), Br (5), I (6), Cp (8), C5H 4Li (10), Ph (11); R = Pr, X = Ph (12)]. Compounds 4 and 8 were converted into the (alkyne)transition-metal complexes 4-Cp2Mo 2(CO)4 (13) and 8-Co2(CO)6 (14), respectively, which were characterized by X-ray diffraction. Stepwise extension and functionalization of the silane chain starting from 1chloro-2-(diethylamino) tetramethyldisilane (Et2NMe2Si-SiMe2Cl) yielded the trisilanes Ph-(SiMe2J3-X [X = NEt2 (18), OMe (19), Cl (20), H (21), C=CPh (22), C=CPr (23)]. The synthesized compounds were characterized by NMR and IR spectroscopy, 4, 11, 13, and 14 also by UV/Vis spectroscopy.
Synthesis of 3,4,5-trisubstituted isoxazoles via sequential [3 + 2] cycloaddition/silicon-based cross-coupling reactions
Denmark, Scott E.,Kallemeyn, Jeffrey M.
, p. 2839 - 2842 (2007/10/03)
(Chemical Equation Presented) A [3 + 2] cycloaddition reaction between alkynyldimethylsilyl ethers and aryl and alkyl nitrile oxides to produce isoxazolylsilanols has been developed. The cross-coupling reactions of these heterocyclic silanols with a varie
Steady state and time-resolved spectroscopic studies of the photochemistry of 1-arylsilacyclobutanes and the chemistry of 1-arylsilenes
Leigh,Boukherroub,Bradaric,Cserti,Schmeisser
, p. 1136 - 1147 (2007/10/03)
Direct photolysis of 1-phenylsilacyclobutane and 1-phenyl-, 1-(2-phenylethynyl)-, and 1-(4'-biphenylyl)-1-methylsilacyclobutane in hexane solution leads to the formation of ethylene and the corresponding 1-arylsilenes, which have been trapped by photolysis in the presence of methanol. Quantum yields for photolysis of the three methyl-substituted compounds have been determined to be 0.04, 0.26, and 0.29, respectively, using the photolysis of 1,1-diphenylsilacyclobutane (Φ(silene) = 0.21) as the actinometer. The corresponding silenes have been detected by laser flash photolysis; they have lifetimes of several microseconds, exhibit UV absorption maxima ranging from 315 to 330 nm, and react with methanol with rate constants on the order of (2-5) x 109 M-1 s-1 in hexane. Absolute rate constants for reaction of 1-phenylsilene and 1-methyl-1-phenylsilene with water, methanol, tert-butanol, and acetic acid in acetonitrile solution have been determined, and are compared to those of 1,1-diphenylsilene under the same conditions. With the phenylethynyl- and biphenyl-substituted methylsilacyclobutanes, the triplet states can also be detected by laser flash photolysis, and are shown to not be involved in silene formation on the basis of triplet sensitization and (or) quenching experiments. Fluorescence emission spectra and singlet lifetimes have been determined for the three 1-aryl-1-methylsilacyclobutanes, 1,1-diphenylsilacyclobutane, and a series of acyclic arylmethylsilane model compounds. These data, along with the reaction quantum yields, allow estimates to be made of the rate constants for the excited singlet state reaction responsible for silene formation. 1-Methyl-1-phenylsilacyclobutane undergoes reaction from its lowest excited singlet state with a rate constant 10-80 times lower than those of the other three derivatives. The results are consistent with a stepwise mechanism for silene formation, involving a 1,4-biradicaloid intermediate that partitions between product and starting material.
Base cleavage of R-SiMen(OMe)3-n bonds (R m-ClC6H4CH2, PhC, or Cl2CH) and alkoxy exchange in RSiMen(OMe)3-n (R = m-ClC6H4CH2)
Chmielecka, Jadwiga,Chojnowski, Julian,Eaborn, Colin,Stanczyk, Wlodzimierz A.
, p. 1779 - 1784 (2007/10/02)
The rates of cleavage of R-SiMen(OMe)3-n bonds (n = 0-3) in NaOMe-MeOH have been measured for R = (i) -ClC6H4CH2, (ii) Ph, and (iii) Cl2CH.The relative reactivities as n is varied in the sequence 3, 2, 1, 0 within each series are: (i) 1,7.2, 2.7, 0.13; (ii) 1, 27, 24, 5.5; (iii) 1, 38, 93, 29.These reactivity variations are discussed in terms of opposition between the rate-enhancing polar effects of the OMe groups and a unusual type of steric affect which arises on introduction of OMe in place of Me.The rates of replacement of one OMe group of m-ClC6H4CH2Men(OMe)3-n by an OEt group in EtOH containing a base have also been measured; in this case the rates rise progressively with the value of n, the relative reactivities for n = 2,1, and 0 being 1, 4.4, and 27, respectively.
Base Cleavage of R-Si Bonds of Silanols RSiMe2OH. A Proposed New Mechanism of Substitution at Silicon
Eaborn, Colin,Stanczyk, Wlodzimierz
, p. 2099 - 2104 (2007/10/02)
Cleavage of R-Si bonds has been found to occur unexpectedly rapidly in solutions of RSiMe2OMe (R = m-ClC6H4CH2 or PhCC) in 5 vol-percent H2O-MeOH containing relatively small concentrations of NaOMe, but with a levelling off of the rate at high concentrations of the base.The behaviour is attributed to the formation of RSiMe2OH and hence RSiMe2O-, and it is suggested that unimolecular dissociation of the silanolate anion RSiMe2O- to give R- and the silianone Me2Si=O (both of which react rapidly with the solvent) plays a significant role.The silanols RSiMe2OH are roughly estimated to have pKa values of 11 (R = m-ClC6H4CH2) and 9.8 (R = PhCC) in water.
