Study on Asymmetric Hydrogenation of Nheterocycles with Sodium Cyanoborohydride and S - (-) – Binol

Hydrogenation is the simplest but most powerful way to produce a wide array of important compounds
in large quantities using inexpensive, clean hydrogen gas without forming any waste. Asymmetric
hydrogenation of Indole-3-aldehydes, Indazole-3-aldehyde and aza indole -3- aldehydes with sodium
cyanoborohydride and s-binol under glac. acetic acid over a period of 1-2 h. gave enantiomeric
excess of 3-substituted 2,3-dihydro alcohols in good yields. This is the first report for the
hydrogenation of aromatic compounds like indoles, indazoles and aza indoles with mild reducing
catalyst Sodium cyanoborohyddride.