Deep eutectic solvents: cutting-edge applications in cross-coupling reactions

Deep eutectic solvents (DESs), surmised as “the organic reaction medium of the century”, have reverberated a new symphony throughout the present green millennium. A brief historical account of the DES systems and their physicochemical properties as task-specific and designer solvents for cross-coupling reactions are appraised including the hole theory that explains the underlying mechanistic pathway for this emerging neoteric medium. The insights into cross-coupling reactions and their applications are included, highlighting the significant achievements pertaining to the dual role of DESs as a solvent and catalyst. In addition, popular “name-reactions” for the carbon–carbon and carbon–heteroatom bond formations related to the nature of DESs and the core optimum conditions are included. The review also encompasses the novel approaches to privileged catalytic systems and identify the voids left in cross-coupling reactions where DES systems have not made inroads yet. Finally, the challenges of utilizing the neoteric derivatives of DES for these reactions are expounded.S. E. H. and R. A. are grateful to the Iran Science Elites Federation (ISEF). D. J. R. gratefully acknowledges financial support from the Spanish Ministerio de Economía, Industria y Competitividad (PGC2018-096616-B-100) and University of Alicante (VIGROB-316FI)