Synthesis 2016; 48(09): 1269-1285
DOI: 10.1055/s-0035-1561336
short review
© Georg Thieme Verlag Stuttgart · New York

Zwitterionic Imidazolium Salt: Recent Advances in Organocatalysis

Sudarshan Das
a   Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: alakananda.hajra@visva-bharati.ac.in
,
Sougata Santra
b   Ural Federal University, Chemical Engineering Institute, Yekaterinburg, 620002, Russian Federation
,
Pallab Mondal
a   Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: alakananda.hajra@visva-bharati.ac.in
,
Adinath Majee
a   Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: alakananda.hajra@visva-bharati.ac.in
,
Alakananda Hajra*
a   Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: alakananda.hajra@visva-bharati.ac.in
› Author Affiliations
Further Information

Publication History

Received: 21 September 2015

Accepted after revision: 23 December 2015

Publication Date:
20 January 2016 (online)


Abstract

Imidazole-based zwitterionic-type molten salts have been explored as a new class of organocatalyst in various chemical transformations. It is known that imidazolium motifs provide an unconventional C–H bond for bonding. It is experimentally proven that C2–H of the imidazole moiety plays a crucial role in catalyzing the reaction via electrophilic activation. This review is based on the role of imidazole-based zwitterionic-type molten salts as an organocatalyst for some useful chemical transformations in organic synthesis. One of the most important features of this catalyst is that it can easily be recovered from the reaction media. The recovered catalyst can be reused for subsequent reactions without losing its catalytic activity significantly.

 1 Introduction

 2 Zwitterionic-type Molten Salt Catalyzed syn-Selective Aza-Henry Reaction

 3 Synthesis of 1-(Amidoalkyl)- and 1-(Carbamatoalkyl)-2-naphthols

 4 Synthesis of 3-Aminoalkylated Indoles

 5 Synthesis of Highly Substituted Imidazoles

 6 Synthesis of 5-Substituted 1H-Tetrazoles by the Cycloaddition of Arenecarbonitriles with Sodium Azide

 7 Synthesis of 4-Arylidene-2-phenyloxazol-5(4H)-ones

 8 Zwitterion-Promoted Ethylene Methoxycarbonylation

 9 Synthesis of 5,6-Unsubstituted 1,4-Dihydropyridines

10 Regioselective Ring Opening of Aziridines

11 Conclusions