4-[(Methylsulfanyl)methyl]morpholine

CAS 61940-55-4, Cat. No EN300-53983882
Reagent for methylthiolation

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4-[(Methylsulfanyl)methyl]morpholine is a bench-stable, odor-reduced methylthiolation reagent developed as an anion-shuttle methylthiolate source¹. Unlike methanethiol or metal thiolates, it releases MeS⁻ in a controlled, low steady-state concentration via a reversible iminium/thiolate equilibrium, which prevents catalyst poisoning. In metal-catalyzed cross-couplings, the reagent enables efficient methylthiolation (–SMe group installation) of a broad range of aryl electrophiles, including chloroarenes, bromoarenes, aryl triflates, tosylates, pivalates, aryl nitriles, and aryl carboxylic acids. It operates under Pd- or Ni-catalysis (ligand-dependent), often with Zn as an additive, and shows excellent functional-group tolerance (ketones, esters, aldehydes, nitro groups, alcohols, heterocycles). Sterically hindered ortho-substituted substrates are less reactive. Overall, the reagent provides a practical, scalable, and odor-safe solution for C–S bond formation, extending methylthiolation to less reactive aryl chlorides and enabling late-stage functionalization of complex molecules.

Synonyms: 4-(methylsulfanylmethyl)morpholine; 4-[(methylthio)methyl]morpholine; N-[(methylthio)methyl]morpholine; NSC 101350