Jump to main content
Jump to site search

Issue 20, 2017
Previous Article Next Article

An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions

Author affiliations

Abstract

A one-pot synthesis of α,β-unsaturated esters from unactivated esters and aldehydes using strong bases, such as sodium alkoxide and potassium tert-butoxide, was reported. However, the ionic liquid (IL) catalyzed probase method for producing α,β-unsaturated esters was not reported until now. In this work, a series of ILs with fluoride anions were firstly prepared and used as catalysts in combination with the probase N,O-bis(trimethylsilyl) acetamide (BSA) for the α,β-unsaturated esters synthesis. This process could also be promoted through the introduction of another IL with Lewis acid sites. The yield and selectivity of the product could reach up to 84.2% and 95.0%, respectively, when [Bmim]F was used in combination with [Bmim]Cl/AlCl3 (the molar fraction of AlCl3 is 0.67). The mechanism investigation through GC-MS indicates that BSA would convert into onium amide, which acted as a strong base for α-H abstraction, with the catalysis of [Bmim]F. Meanwhile, [Bmim]Cl/AlCl3 played an important role in the condensation step between enolates and aldehydes. On the basis of mechanism insights, kinetic and thermodynamic studies were also carried out for a better understanding of this new route.

Graphical abstract: An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions

Back to tab navigation

Supplementary files

Publication details

The article was received on 26 Jul 2017, accepted on 24 Aug 2017 and first published on 04 Sep 2017


Article type: Paper
DOI: 10.1039/C7GC02265D
Citation: Green Chem., 2017,19, 4838-4848
  •   Request permissions

    An ionic liquid catalyzed probase method for one-pot synthesis of α,β-unsaturated esters from esters and aldehydes under mild conditions

    G. Wang, Y. Xu, S. Zhang, Z. Li and C. Li, Green Chem., 2017, 19, 4838
    DOI: 10.1039/C7GC02265D

Search articles by author

Spotlight

Advertisements