Disulfides, reaction with boranes

Ignition or explosive reaction with metals (e.g., aluminum, antimony powder, bismuth powder, brass, calcium powder, copper, germanium, iron, manganese, potassium, tin, vanadium powder). Reaction with some metals requires moist CI2 or heat. Ignites with diethyl zinc (on contact), polyisobutylene (at 130°), metal acetylides, metal carbides, metal hydrides (e.g., potassium hydride, sodium hydride, copper hydride), metal phosphides (e.g., copper(II) phosphide), methane + oxygen, hydrazine, hydroxylamine, calcium nitride, nonmetals (e.g., boron, active carbon, silicon, phosphoms), nonmetal hydrides (e.g., arsine, phosphine, silane), steel (above 200° or as low as 50° when impurities are present), sulfides (e.g., arsenic disulfide, boron trisulfide, mercuric sulfide), trialkyl boranes. 

Trialkylboranes react with organic disulfides to give thioethers (sulfides) but air or light is required because tbe reaction proceeds by a radical chain process.This reaction is very slow in the dark and ultraviolet (UV) light is required for reasonable reaction rates. Tri octyl borane reacts with dimethyl disulfide under these conditions to give methyl 1-octyl sulfide in 95% yield. 6 The mixed borane B-cyclohexyl-3,5-dimethylborinane (220), gave 94% of cyclohexyl methyl sulfide (221) under the same conditions. ... 

The disulfide is obtained from the monosulfide with sulfur in boiling toluene (method A). The reaction is very slow but gives a high yield, and the disulfide is not contaminated with side products. The pure borane with mp 134-135° is isolated directly as a residue of concentrating the reaction mixture under vacuum or also by filtration the suspension. 

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