Dithiodiglycolic anhydride undergoes an efficient formal cycloaddition with imines to afford functionalized 4-thiazolidinones, without complications arising from the anhydride-imine reaction or the sulfa-Michael reaction (in the case of 1,3-azadienes).

The contra-thermodynamic halolactonization of lactam-tethered 5-aryl-4(E)-pentenoic acids, under solvent- and catalyst-controlled conditions, has facilitated the efficient and stereocontrolled synthesis of halogenated fused γ-lactone-lactams.

The catalytic halolactonization of readily affordable γ-lactam-tethered alkenoic acids has facilitated the site-selective, efficient, and stereocontrolled synthesis of halogenated fused γ-lactam-δ-lactones.

A flexible approach to sp3-rich N-heterocyclic sulfones, which hinges on the efficient annulation of an easy-to-prepare sulfone-embedded anhydride with 1,3-azadienes and aryl aldimines, is described.

Versatile amino-1,3-dienes have been prepared in a stereocontrolled manner, by engaging thiomorpholinone-tethered alkenoic acids in a cascade process featuring base-mediated esterification, C–S bond cleavage, and concomitant 1,2-styryl migration.