Guanidine derived ionic liquids: catalyst free medium for N-formylation of amines

Jafar Akbari,Mehdi Sheykhan,Akbar Heydari,Malak Hekmati

doi:10.3998/ark.5550190.0010.b12

Abstract

A remarkable improvement of both the chemical yield and the reaction condition, of N- formylation of amines with formic acid was found, when tetra-substituted guanidinium salts were added as ionic liquids. Effects of amount and the type of guanidinium salts on the outcome of the reaction were investigated. This procedure works well for sterically hindered primary amine as well as electron-deficient primary arylamines, primary and secondary amino alcohols, α-amino acid esters, hydroxylamines and N,N-dimethylhydrazine. The recovered ionic liquid can be recycled for four runs without loss of activity

Highlights

One of the most useful and versatile functional groups to be introduced into an organic molecule is the formyl group
Formamides have been widely used in organic synthesis as protecting group of amines,[1] precursor for isocyanide preparation,[2, 3] an intermediate for mono methylated of primary amines.[4]
They have been used in the synthesis of formamidines.[5]

Summary

Introduction

One of the most useful and versatile functional groups to be introduced into an organic molecule is the formyl group. Formamides have been widely used in organic synthesis as protecting group of amines,[1] precursor for isocyanide preparation,[2, 3] an intermediate for mono methylated of primary amines.[4] In addition, they have been used in the synthesis of formamidines.[5] a number of formylating methods have been reported. Acetic formic anhydride[6] continues to be the most widely used formylating reagent, but it is sensitive to atmospheric moisture and cannot be stored due to decomposition to acetic acid and carbon monoxide. Many other useful formylation reagents have been reported such as chloral,[7] activated formic acid using DCC8 or EDCI,[9] activated formic esters,[10] ammonium formate,11 2,2,2-trifluoroethyl formate[12] and aq. There is still scope to develop a simple and practical method for the N-formylation of amines under mild conditions

Methods

Results

Conclusion