Synthesis of functionalized chiral ammonium, imidazolium, and pyridinium-based ionic liquids derived from (−)-ephedrine using solvent-free microwave activation. Applications for the asymmetric Michael addition

Chiral ionic liquid crystals based on thiourea

Chiral ionic liquid crystals based on the S-methyl-N,N′-α-methylarylthiouronium cation have been prepared and studied.

The Beneficial Sinergy of MW Irradiation and Ionic Liquids in Catalysis of Organic Reactions

The quest for sustainable processes is becoming more and more important, with catalysis playing a major role in improving atom economy and reducing waste. Organic syntheses with less need of protecting/de-protecting steps are highly desirable. The combination of microwave irradiation, as energy source, with ionic liquids, as both solvents and catalysts, offered interesting solutions in recent years. The literature data of the last 15 years concerning selected reactions are presented, highlighting the importance of microwave (MW) technology coupled with ionic liquids.

Bond cleavage, fragment modification and reassembly in enantioselective three-component reactions

Chemical bond cleavage and reconstruction are common processes in traditional rearrangement reactions. In contrast, the process that involves bond cleavage, fragment modification and then reconstruction of the modified fragment provides an efficient way to build structurally diversified molecules. Here, we report a palladium(II)/chiral phosphoric acid catalysed three-component reaction of aryldiazoacetates, enamines and imines to afford α-amino-δ-oxo pentanoic acid derivatives in good yields with excellent diastereoselectivities and high enantioselectivities. The stereoselective reaction went through a unique process that involves cleavage of a C–N bond, modification of the resulting amino fragment and selective reassembly of the modified fragment. This innovative multi-component process represents a highly efficient way to build structurally diversified polyfunctional molecules in an atom and step economic fashion. A keto-iminium is proposed as a key intermediate and a chiral palladium/phosphate complex is proposed as an active catalyst.

Multi-component reactions allow complex structures to be rapidly built from simple starting materials. Here, the authors report an enantioselective three-component coupling of imines, enamines and aryldiazoacetates catalysed by a phosphinic acid and palladium(II).

N-Heterocyclic carbene-catalyzed synthesis of functionalized 3-hydroxypyrrolidinones via a domino aza-Michael/aldol reaction

The reaction features a transition-metal-free approach, mild reaction conditions, as well as a simple procedure.

Basic-functionalized recyclable ionic liquid catalyst: A solvent-free approach for Michael addition of 1,3-dicarbonyl compounds to nitroalkenes under ultrasound irradiation

A task-specific ionic liquid (TSIL) has been introduced as a recyclable catalyst in Michael addition. A series of nitroalkenes and various C-based nucleophiles were reacted in the presence of 30mol% of recyclable basic-functionalized ionic liquid. Good to excellent yields were obtained in 30min under ultrasound irradiation.

Recent development in functionalized ionic liquids as reaction media and promoters

The recent development in the use of functionalized ionic liquids as both reaction media and promoters is reviewed. Ionic liquids designed with special functionality can enhance the reaction rate, selectivity, and productivity in various chemical reactions. In this context, some important chemical reactions involving C–C, C–O, C–N, and C–S bond formation in functionalized ionic liquids are discussed. These functionalized ionic liquids were found to provide distinct advantages over conventional organic solvents in these catalytic reactions.

Synthesis of New Ferrocene bis Thiocarbazones under Solvent-Free Conditions using Microwave

A simple efficient method for the synthesis of new ferrocene bis thiocarbazones via microwave irradiation under solvent-free conditions has been developed. Compared to the conventional method, its major advantages are short reaction times, good conversions and actually accorded the green synthesis technology. The structures of target compounds were confirmed by 1H NMR, IR, ESI-MS spectra data and elemental analysis. Preliminary bioassay results showed that some of these compounds possess inhibitory effects against S. aureus, S. pyogenes and E. coli bacteria.