Metal-free Deoxygenation of Chiral Nitroalkanes: an Easy Entry to α-substituted Enantiomerically Enriched Nitriles.

Abstract

A metal-free, mild and chemodivergent transformation involving nitroalkanes was developed. Under optimized reaction conditions, in the presence of trichlorosilane and a tertiary amine, aliphatic nitroalkanes have been 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 in 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 APIs (Ibuprofen, Tembamide, Aegeline and Denopamine).