Rapid Reduction of Organic Functionalities Using Samarium Diiodide

Abstract

Recent study in this laboratory is reviewed. The single electron donor ability of samarium diiodide (Sml2) can be enhanced with ligands around of Sm(II) when a sufficient electron is supplied from ligands. Mechanistic consideration of this enhancement led us to find that carboxylic acid, ester, amide, nitrile and the other functionalities were rapidly reduced with Sml2 in the presence of base, acid and water as ligands at room temperature in good yields. Particularly, these systems reduced directly carboxylic acid into alcohol and SmI2-85% phosphoric acid system reduced aromatic primary amide to aldehyde in good yield. Pyridines were similarly reduced to piperidines with Sml2-base or water system and aromatic nucleus of phenol derivatives was rapidly reduced with Sml2-base system. Furthermore, carboxylic acid, ester, amide and nitrile were rapidly reduced with Sm or Yb metal-hydrochloric acid system. The striking characteristic of these reduction is mild conditions, short reaction time (within a few seconds — minutes), high yield of reductive products and one pot reaction with facile method. © 1994, The Society of Synthetic Organic Chemistry, Japan. All rights reserved.