Used primarily as a protecting group in organic synthesis, particularly for thiols. The trimethylsilanyl group stabilizes the thiol during reaction sequences and can be removed selectively under mild conditions, such as with fluoride ions or weak acid, to regenerate the free thiol. This makes it valuable in multi-step syntheses, especially in peptide chemistry and pharmaceutical intermediates where sulfur-containing functional groups need temporary masking. Its volatility and stability also make it useful in analytical chemistry for derivatization of thiol compounds prior to gas chromatography or mass spectrometry.