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Product Code: SIT8430.0

Cas No: 2857-97-8

R&D quantities:

2.5 kg
25 g

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Trimethylsilyl Blocking Agent

Used as a protecting group for reactive hydrogens in alcohols, amines, thiols, and carboxylic acids. Organosilanes are hydrogen-like, can be introduced in high yield, and can be removed under selective conditions. They are stable over a wide range of reaction conditions and can be removed in the presence of other functional groups, including other protecting groups. The tolerance of silylated alcohols to chemical transformations summary is presented in Table 1 of the Silicon-Based Blocking Agents brochure.

Trimethylbromosilane; Bromotrimethylsilane; Trimethylsilyl bromide; TMBS
  • More reactive than SIT8510.0 Less reactive, but more Less reactive, photolytically stable than SIT8564.0
  • Nafion SAC-13 has been shown to be a recyclable catalyst for the trimethylsilylation of primary, secondary, and tertiary alcohols in excellent yields and short reaction times
  • Summary of selective deprotection conditions is provided in Table 7 through Table 20 of the Silicon-Based Blocking Agents brochure
  • Boiling Point: 80°

    EINECS Number: 220-672-0

    Melting Point: -44°

    Molecular Weight: 153.09


    Specific Gravity: 1.1725

    Flashpoint: -3°C (27°F)

    HMIS Key: 3-4-2-X

    Hydrolytic Sensitivity: 8: reacts rapidly with moisture, water, protic solvents

    Formula: C3H9BrSi

    Refractive Index: 1.422


    Application: Review of synthetic utility.1
    Converts acid chlorides to acid bromides.2
    Deesterifies phosphorus esters.3
    Converts nitroalkanes to nitroalkenes.4
    Catalyzes the cross-coupling of heteroaromatics.5
    Used in the synthesis of unsymmetrical phosphine oxides.6

    Reference: 1. Handbook of Reagents for Organic Synthesis, Reagents for Silicon-Mediated Organic Synthesis, Fuchs, P. L. Ed., John Wiley and Sons, Ltd., 2011, p. 92-100.
    2. Schmidt, A. H. et al. Synthesis 1981, 216.
    3. Chovinard, P. M.; Bartlett, P. A. J. Org. Chem. 1986, 51, 75.
    4. Kunetsky, R. A. et al. Tetrahedron Lett. 2005, 46, 5203.
    5. Kita, Y. et al. J. Am. Chem. Soc. 2009, 131, 1668.
    6. Fougére, C. et al. Eur. J. Org. Chem. 2009, 6048.

    Fieser: F&F: Vol. 9, p 73; Vol. 10, p 59; Vol. 11, p 59; Vol. 12, p 799; Vol. 15, p 51; Vol. 16, p 50; Vol. 18, p 380; Vol. 19, p 373; Vol. 20, p 404.

    Additional Properties: Dipole moment: 2.34 debye
    Ionization potential: 10.24 eV
    ?Hform: -70.3 kcal/mole
    ?Hvap: 30.8 kj/mole