Deep Eutectic Solvent as a Sustainable Medium for C–C Bond Formation Via Multicomponent Radical Conjugate Additions

Abstract

Deep eutectic solvents (DESs) have been used for the first time as a sustainable medium in radical-mediated molecular organic synthetic protocols. This study reports an efficient protocol for the C−C bond formation through radical conjugate addition of simple olefins (di-and trisubstituted). An inexpensive and abundant iron catalyst [Fe(acac) 3 ] together with nontoxic silane (poly(methylhydrosiloxane) (PMHS)) was employed, using choline chloride/ethylene glycol (1:2) as a solvent under air and mild reaction conditions. Different functional groups were well tolerated, and also, the reaction could be carried out on a gram scale with excellent yields.

Unlocking the Potential of Deep Eutectic Solvents for C–H Activation and Cross-Coupling Reactions: A Review

“…The activation process involves the formation of a hydrogen bond between the carbonyl group of the substrate and the HBD moiety of the DES. This interaction enhances the electrophilicity of the carbonyl group, facilitating the formation of the desired α-substituted product [47,48].…”

Deep Eutectic Solvents as à-la-Carte Medium for Transition-Metal-Catalyzed Organic Processes

“…The addition of di- and tri-substituted unactivated alkenes to electron-deficient olefins was achieved by employing Fe(acac) 3 as a catalyst and the inexpensive and non-toxic poly(methylhydrosiloxane) as a reducing agent. Reactions were carried out for 2 h at 60 °C, and 16 examples were reported with yields ranging from 48 to 98% ( Figure 36 , Table 5 , entry 9) [ 106 ].…”

Preparation of polysubstituted imidazoles using AC-SO3H/[Urea]7[ZnCl2]2as an efficient catalyst system: a novel method, and α-glucosidase inhibitor activity

“…[38][39][40] Deep eutectic solvents (DESs) have received a great deal of interest in the last ten years in both starting materials and catalysts because of their distinctive qualities, including their large liquid range, biodegradability, outstanding thermal stability, and moderate vapor pressure. 41,42 Since the rst one was made by Abbott's group in the year 2001, a number of other DESs have indeed been discovered as solvents and catalysts for organic transformations such as the creation of carboncarbon [43][44][45] and carbon-heteroatom 46 bonding, as well as multicomponent reactions. DESs have been employed in a wide range of applications, including the extraction of cellulose, 47 chitin, 48 polysaccharides, 49 lipids, 50 and other polarity chemicals, 51 as well as the electrolyte in dye-sensitized solar cells, [52][53][54] lithium-ion batteries, [55][56][57] and electrochemical double-layer capacitors.…”