Zn(BH4)2/2NaCl: A Novel Reducing System for Efficient Reduction of Organic Carbonyl Compounds to Their Corresponding Alcohols

Zn(BH4)2/2NaCl, obtained by the reaction of ZnCl2 and NaBH4 ,is a stable, efficient and selective reducing system in dry-THF. The Zn(BH4)2/2NaCl system (0.5–1 mmol) reduces a variety of carbonyl compounds to their corresponding alcohols in CH3CN at room temperature in high to excellent yields.KEYWORDS Reduction, carbonyl compounds, Zn(BH4)2, chemoselective, regioselectivity, NaCl

Convenient Reduction of Carbonyl Compounds to their Corresponding Alcohols with NaBH4/(NH4)2C2O4 System

Sodium borohydride (0.4–1.5 equivalents) in the presence of ammonium oxalate (0.2 equivalents) reduces varieties of organic carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and α,β-unsaturated carbonyl compounds to their corresponding alcohols. Reduction reactions were carried out in acetonitrile in high to excellent yields of products. Thechemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing system. In addition, regioselectivity and exclusive 1,2-reduction of conjugated carbonyl compounds to their corresponding allylic alcohols in high to excellent yields was achieved successfully with this reducing system.Keywords: Sodium borohydride, reduction, carbonyl compounds, ammonium oxalate, chemoselective, regioselectivit

Synthesis of 2-(5-Nitropyrid-2-yl)-3-(4-substitutedphenyl)aminoisoxazol-5(2H)-ones and Their Rearrangements to Imidazo[1,2-a]- pyridines and Indoles with Triethylamine

3-(4-Substitutedphenyl)aminoisoxazol-5(2H)-ones, substituted on nitrogen with a nitropyridine group, react with triethylamine to give imidazo[1,2-a]pyridines and indoles. With 4-bromophenyl and 4-methylphenyl group substituents only imidazopyridines are formed, but the 4-methoxyphenyl derivative gave a 3:1 mixture of the corresponding imidazo[1,2-a]pyridine and 2-pyridylaminoindole, respectively