<p>Here Ni-catalysed multicomponent reductive cross-coupling of thiourea dioxide, aziridines and alkyl halides is disclosed, enabling the divergent synthesis of β-amino sulfides and disulfides. The β-amino sulfides are selectively synthesized using a planar bidentate 2,9-dimethyl-1,10-phenanthroline ligand through a Ni^I/Ni^III catalytic cycle. Moreover, the non-planar bidentate ligand 6,6′-dimethyl-2,2′-dipyridyl, possessing an axial torsional dihedral angle, affords β-amino disulfides via a Ni⁰/Ni^II/Ni^I catalytic cycle. Density functional theory calculations demonstrate that the planar bidentate ligand converts the catalytic centre from Ni^I–SR to a Ni^III species via oxidative addition with a monosulfurating transformation, and the non-planar bidentate ligand induces the dimerization of Ni^I–SR, forming a sulfido-bridged dimer for disulfurating transformations. Clinically applied pharmaceuticals, such as bezafibrate, indometacin and thalidomide, with reactive functional groups, are compatible with the versatile sulfuration linkage, demonstrating the applicability of this strategy.</p><p></p>