Deep Eutectic Mixtures: Promising Sustainable Solvents for Metal‐Catalysed and Metal‐Mediated Organic Reactions

Abstract

This microreview is intended to cover the progress made in metal-mediated and metal-catalysed organic reactions performed in a new family of inexpensive, greener and biorenewable eutectic mixtures, the so-called Deep Eutectic Solvents (DESs), as environmentally friendly reaction media. This ambitious research is focused on studies of particular interest in organometallic chemistry, in search of synthetic strategies able to optimise the overall process in an ecofriendly manner. This microreview aims to provide an over- [a]5147 view of the application of DESs in the fields of: (i) Ru-and Au-catalysed isomerisation and cycloisomerisation of organic substrates, (ii) Cu-catalysed click chemistry and C-C bondformation reactions, (iii) Pd-catalysed cross-coupling processes and Tsuji-Trost reactions, (iv) Rh-catalysed hydrogenation and hydroformylation of alkenes, (v) addition of RMgX and RLi compounds to ketones, and (vi) regioselective orthoand lateral lithiation of aryltetrahydrofurans.

Deep eutectic solvents: designer fluids for chemical processes

“…García‐Álvarez presented a micro‐review on the use of DESs as environmentally friendly reaction media in metal‐catalyzed and metal‐mediated organic reactions. The catalyst activity of bis(allyl)‐ruthenium(IV) complexes in the isomerization of allylic alcohols was investigated in the presence of different DESs.…”

Organic Synthesis without Conventional Solvents

“…[1,3,172,173] However, in contrast to ILs, most DES are easily available from renewable feedstock, are biodegradable, cheap, and non-toxic.…”

Deep eutectic solvent as a green solvent for enhanced extraction of narirutin, naringin, hesperidin and neohesperidin from Aurantii Fructus

“…Obviously, these excellent properties of DESs have been highlighted by their widespread applications in many branches of chemistry. Up to now, DESs as green and sustainable media were extensively used in the fields of catalysis, electrochemistry, material chemistry, biochemistry, biology and organic synthesis . Currently, DESs, as another emerging solvent replacing traditional organic solvents, are being used to extract bioactive compounds, such as flavonoids, phenolic acids, polyphenols, tanshinones, rosiglitazones, saponins, and anthraquinones from various types of natural sources .…”

“…biology and organic synthesis. [6][7][8][9][10][11][12] Currently, DESs, as another emerging solvent replacing traditional organic solvents, are being used to extract bioactive compounds, such as flavonoids, phenolic acids, polyphenols, tanshinones, rosiglitazones, saponins, and anthraquinones from various types of natural sources. [13][14][15][16][17][18][19] The conventional extraction solvents, such as methanol, ethyl acetate, ethanol and so on, are hazardous and flammable, and there is inadequate disposal for the solvents, while DESs can solve these problems effectively.…”