Diphenyl disulfide (PhSSPh), a typical boryl monosulfide (diiPr‐Imd‐BH2SPh) and a typical boryl bis‐sulfide [diMe‐Imd‐BH(SPh)2] all serve as both initiators and precatalysts in the reduction of alkyl and aryl halides by readily available 1,3‐dimethylimidazol‐2‐ylidene⋅borane (diMe‐Imd‐BH3). The reactions are suggested to occur by a polarity reverse catalysis mechanism where in situ generated thiophenol is the active catalyst.