Metal-Free Deoxygenation of Chiral Nitroalkanes : An Easy Entry to α-Substituted Enantiomerically Enriched Nitriles

A metal-free, mild and chemodivergent transformation
involving nitroalkanes has been developed.
Under optimized reaction conditions, in the presence of
trichlorosilane and a tertiary amine, aliphatic nitroalkanes
were selectively converted into amines or nitriles. Furthermore,
when chiral β-substituted nitro compounds were
reacted, the stereochemical integrity of the stereocenter
was maintained and α-functionalized nitriles were obtained
with no loss of enantiomeric excess. The methodology was
successfully applied to the synthesis of chiral β-cyano
esters, α-aryl alkylnitriles, and TBS-protected cyanohydrins,
including direct precursors of four active pharmaceutical
ingredients (ibuprofen, tembamide, aegeline and denopamine).