TRIMETHYLCHLOROSILANE

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.

Aliphatic, fluorinated aliphatic or substituted aromatic hydrocarbon substituents are the hydrophobic entities which enable silanes to induce surface hydrophobicity. The organic substitution of the silane must be non-polar. The hydrophobic effect of the organic substitution can be related to the free energy of transfer of hydrocarbon molecules from an aqueous phase to a homogeneous hydrocarbon phase. A successful hydrophobic coating must eliminate or mitigate hydrogen bonding and shield polar surfaces from interaction with water by creating a non-polar interphase. Although silane and silicone derived coatings are in general the most hydrophobic, they maintain a high degree of permeability to water vapor. This allows coatings to breathe and reduce deterioration at the coating interface associated with entrapped water. Since ions are not transported through non-polar silane and silicone coatings, they offer protection to composite structures ranging from pigmented coatings to rebar reinforced concrete. A selection guide for hydrophobic silanes can be found on pages 22-31 of the Hydrophobicity, Hydrophilicity and Silane Surface Modification brochure.

Viscosity: 0.47 cSt

ΔH_comb: -2,989 kJ/mol

ΔH_form: -354 kJ/mol

ΔH_vap: 27.6 kJ/mol

Dipole moment: 2.09 debye

Surface tension: 17.8 mN/m

Specific heat: 1.76 J/g/°C

Coefficient of thermal expansion: 1.2 x 10^-3

Vapor pressure, 20 °: 190 mm

Vapor pressure, 50 °C: 591 mm

Critical temperature: 224.6 °C

Critical pressure: 31.6 atm

Most economical and broadly used silylation reagent

Enhances Claisen rearrangement

Enhances the deprotection of tBOC-protected amino acids

Enhances ethylene glycol ketalization reaction

Catalyzes the formation of chlorohydrin esters from diols

Reviewed as water scavenger in reactions of carbonyl compounds

Facilitates Michael additions

Reacts in presence of HCl acceptor

Will silylate strong acids with expulsion of HCl

High purity grade available, SIT8510.1

Protects hindered alcohols with Mg/DMF

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