The simplest α,α-disubstituted thiocarboxylic S-acid. The bulky tert-butyl group blocks α-hydrogens, imparting high hydrolytic and oxidative stability to the thiol function, while the electron-withdrawing carbonyl lowers the pKa of the –SH to ≈ 5.05. These features make thiopivalic acid a versatile molecular toolbox for:
Julia-Kocienski olefination reagent: the derived tetrazol-5-yl sulfone is shelf-stable and delivers >90 % (E)-selectivity in one-pot Julia couplings to construct fluorinated stilbenes and agrochemical intermediates .
High-flux RAFT chain-transfer agent: the sterically hindered tertiary thio-acid yields narrowly dispersed (Đ <1.10) poly(meth)acrylate macro-CTAs for block-copolymer lithography and 3-D printing resins .
FEMA-GRAS meat flavour precursor: enzymatic oxidation generates the corresponding disulfide, a roast-beef, onion-like odorant (threshold 0.03 ng L⁻¹) used in savoury seasonings at 0.1–5 ppm .
Heavy-metal scavenger: the soft thiocarbonyl sulfur forms a stable 1 : 1 complex with Pd(II) (log K = 17.8), enabling recovery of palladium from spent cross-coupling liquors to <0.2 ppm residual .
UV-B-absorbing functional monomer: incorporated at 1–3 wt % into acrylic latexes it imparts broad-spectrum UV-B absorption (λmax 295 nm, ε 16 000) for clear sunscreen films and optical coatings .
Store under nitrogen at 2–8 °C, away from light and oxidants to suppress disulfide formation.
