- Preparation method of 1,3-diphenyl-1,1,3,3-tetramethyl disiloxane
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The invention discloses a preparation method of 1,3-diphenyl-1,1,3,3-tetramethyl disiloxane. The preparation method is characterized in that the Wurtz method or Grignard method is adopted, and 1,3-diphenyl-1,1,3,3-tetramethyl disiloxane is synthesized through disiloxane rectified from an organosilicon high-boiling component and a halogenated compound. According to the preparation method, market application and high-value utilization of the organosilicon high-boiling component are expanded, and a raw material basis can be further provided for preparation of organosilicon materials with special functions.
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Paragraph 0017
(2017/05/25)
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- Allyldimethylsilyl triflate: a self-catalyzed silyl nucleophile
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Allyldimethylsilyl triflate 2 may be prepared by a protiodesilylation reaction between diallyldimethylsilane and triflic acid.This compound possesses both a silyl-substituted carbon nucleophile and the Lewis acid necessary for activation of an electrophile.Upon exposure to an aromatic aldehyde (e.g., p-MeOC6H4CHO), the homoallylic alcohol 4 is formed in good yield.The synthetic advantages of the intramolecular Cope-type cyclization reactio are discussed.
- Brook, Michael A.,Crowe, Grant D.,Hiemstra, Henk
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p. 264 - 268
(2007/10/02)
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- Proton Addition to Silylstyrenes: Overcoming the Predilection for Protiodesilylation
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Normally, organosilyl nucleophiles such as vinylsilanes and allylsilanes undergo protiodesilylation reactions with protons.To favour addition reactions under these conditions, the ligands on silicon have been modified such that the leaving group ability and, simultaneously, the β-effect of the silyl group is reduced.In the case of allylsilanes, the use of dichlorosilyl groups does not significantly favour addition over substitution processes at the olefin.However, with vinylsilanes bearing a second ?-nucleophile, a dichlorosilyl group can be used to regioselectively direct the formation of two bonds (C-H and C-C) sequentially in a process in which the silicon is not lost from the molecule, but may ultimately be cleaved leading to the formation of diols.Thus, benzyldichlorostyrylsilane 7, after cyclization to 9 in the presence of triflic acid, is converted into diol 12.The synthetic utility of this process is restricted by the relatively low reactivity of the styryl ?-system and the necessarily reactive electrophiles needed to initiate the process.The effect of changing from electron-donating groups to electronegative groups on silicon on reaction mechanism is discussed.
- Henry, Courtney,Brook, Michael A.
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p. 11379 - 11390
(2007/10/02)
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