The three-center-four-electron halogen bond (3c4e X-bond) presents a new design concept for catalysis. By integrating halogen(I) (X+: I+ or Br+), bis-pyridyl ligand NN, and non-nucleophilic counter anion Y, we developed non-metallic complex catalysts, N···X···NYs, which exhibited outstanding activity and facilitated the Mukaiyama–Mannich-type reaction of N-heteroaromatics with ppm-level catalyst loading. The high activity of N···X···NSbF6 was clearly demonstrated. NMR titration experiments, CSI-MS, computations, and UV-vis spectroscopic studies suggest that the robust catalytic activity of N···X···NY can be attributed to the unique feature of the 3c4e X-bond for binding chloride: i) the partial covalent nature transforms N···X···N+ complexation to sp2CH as a hydrogen bonding donor site, and ii) the noncovalent property allows for the dissociation of N···X···N+ for the formation of Cl···X···Cl–. This study introduces a new application of 3c4e X-bonds for catalysis via halogen(I) complexes.