Search results
Results from the WOW.Com Content Network
When attached to certain functional groups in a reactant molecule, trimethylsilyl groups may also be used as temporary protecting groups during chemical synthesis or some other chemical reactions. In chromatography, derivitization of accessible silanol groups in a bonded stationary phase with trimethylsilyl groups is referred to as endcapping.
The general structure is R 1 R 2 R 3 Si−O−R 4 where R 4 is an alkyl group or an aryl group. Silyl ethers are usually used as protecting groups for alcohols in organic synthesis . Since R 1 R 2 R 3 can be combinations of differing groups which can be varied in order to provide a number of silyl ethers, this group of chemical compounds ...
The exchange of a protecting group from a methyl ether to a MOM-ether inhibits here the opening of an epoxide to an aldehyde. Protecting group chemistry finds itself an important application in the automated synthesis of peptides and nucleosides. The technique was introduced in the field of peptide synthesis by Robert Bruce Merrifield in 1977 ...
The products after silylation, namely silyl ethers and silyl amines, are resilient toward basic conditions. [2] Protection is typically done by reacting the functional group with a silyl halide by an SN2 reaction mechanism, typically in the presence of base. [3] The protection mechanism begins with the base deprotonating the alcohol group.
Alcohol 27 (Scheme 3) was protected as the BOM ether, a more robust protecting group than MOP (see below). Carbonate (asymmetric) phosgene, pyridine, ethanol in dichloromethane, -23 to -10 °C sodium bis(2-methoxyethoxy)aluminumhydride The secondary alcohol in the 4-pentenal product of the aldol reaction, 9, was protected as an asymmetric ...
A silanol is a functional group in silicon chemistry with the connectivity Si–O–H. It is related to the hydroxy functional group (C–O–H) found in all alcohols. Silanols are often invoked as intermediates in organosilicon chemistry and silicate mineralogy. [1] If a silanol contains one or more organic residues, it is an organosilanol.
The heat of evaporation is 45.64 kJ·mol −1, the evaporation entropy 123 J·K −1 ·mol −1. [2] The vapor pressure function according to Antoine is obtained as log 10 (P/1 bar) = A − B/(T + C) (P in bar, T in K) with A = 5.44591, B = 1767.766 K and C = −44.888 K in a temperature range from 291 K to 358 K. [ 2 ] Below the melting point ...
The general structure of a silyl enol ether. In organosilicon chemistry, silyl enol ethers are a class of organic compounds that share the common functional group R 3 Si−O−CR=CR 2, composed of an enolate (R 3 C−O−R) bonded to a silane (SiR 4) through its oxygen end and an ethene group (R 2 C=CR 2) as its carbon end.