Metal-Free Syntheses of α‑Ketothioamide and α‑Ketoamide Derivatives from Sulfoxonium Ylides

An efficient base, additive and metal-free
synthetic methods for
α-ketothioamide and α-ketoamide derivatives from readily
available sulfoxonium ylides have been described. Sulfoxonium ylides
with primary or secondary amines afforded α-ketothioamides in
the presence of elemental sulfur, whereas α-ketoamides were
produced when I2 and TBHP were present. The reaction proceeded
well at room temperature and generated the corresponding molecules
in good to excellent yields. The reaction can be scaled-up and tolerated
by a range of functional groups with simple operational procedures.