Title:Applications of Choline Chloride-Based Deep Eutectic Solvents as Sustainable Media
and Catalyst in the Synthesis of Heterocyclic Scaffolds
Volume: 26
Issue: 8
Author(s): Sonia Ratnani, Savita Bargujar, Mihir Khulbe and Abha Kathuria*
Affiliation:
- Department of Chemistry, Ramjas College, University of Delhi, Delhi - 110007, India
Keywords:
Deep eutectic solvents, ionic liquids, heterocyclic compounds, choline chloride, organic synthesis, green chemistry.
Abstract: Deep eutectic solvents (DESs), also referred to as low transition temperature mixtures
(LTTMs), have emerged as sustainable and cheap alternatives to conventional organic
solvents in organic synthesis. This is attributed to their exceptional characteristics viz. easy
preparation with readily available cheap materials, water compatibility, non-flammability,
non-toxicity, biocompatibility, biodegradability, etc. All these properties label them as versatile
and cost-effective green solvents. The first reported DES, choline chloride urea mixture
has appeared as an innocuous solvent and catalyst in many organic transformations. This prospective
DES combination has been applied extensively to the synthesis of a wide range of
heterocyclic compounds including quinolones, spirooxindoles, etc. The conditions employed
are relatively mild and do not require additional acid catalysts or organic solvents. This ecofriendly
blend for the synthesis of heterocycles reports excellent yields of products with shorter reaction times and a
simple workup procedure. Evaluating these merits, this review focuses on the recent literature published on the use
of choline chloride-based DESs in the synthesis of a few important heterocyclic compounds.
