Microwave-promoted direct amidation of unactivated esters catalyzed by heteropolyanion-based ionic liquids under solvent-free conditions

Tethered NHC Ligands for Stereoselective Alkyne Semihydrogenations

“…NMR (125 MHz, CDCl 3 ): δ = 14.1, 63.9, 120.0, 125.7, 129.4, 136.5, 154.0, 161.2. HRMS (ESI): m/z calcd for C 10 H 12 NO 3 + [(M + H) + ]: 194.0812; found: 194.0804.The data are in accordance with the literature 38.…”

Metal‐Free Synthesis of N‐Aryl Amides using Organocatalytic Ring‐Opening Aminolysis of Lactones

“…These harsh reaction conditions, however, may limit the functional group tolerance, scalability, and practical application of these processes, and moreover a substantial amount of waste and metal residues are produced. To the best of our knowledge, the only known catalytic approach for the ROA of a non‐strained lactone in the presence of an aromatic amine requires a tungstate‐based catalyst under microwave conditions at temperatures above 100 °C with a fairly limited scope . Therefore, the development of a general catalytic ROA strategy involving readily available lactones under metal‐free and attractive mild conditions enabling the preparation of N ‐aryl amides has significant incentives.…”

An Efficient, Eco-friendly and Sustainable One-Pot Synthesis of 3,4-Dihydropyrimidin-2(1H)-ones Directly from Alcohols Catalyzed by Heteropolyanion-Based Ionic Liquids

“…Based on our previous investigations into HPAILs catalyzed reactions [ 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 ], N -substituted imidazole, pyridine and triethylamine based HPAILs were chosen as potential catalysts for this tandem oxidative cyclocondensation ( Figure 1 ).…”

“…Recently, a large number of publications have clearly shown that the main benefit of microwave (MW) chemical processing is the significant rate enhancements, yield and selectivity improvements as well as less environmental pollution, matching with the goals of green chemistry [ 100 , 101 , 102 ]. Following our continued investigation into the development of useful and sustainable synthetic methodologies [ 103 , 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 ]—along with recent investigations involving oxidation of alcohols and the subsequent trapping of carbonyl intermediates with appropriate nucleophiles in a one-pot operation. [ 112 ]—herein, we report an efficient and environmentally benign TOPs for the Biginelli reaction, starting directly from alcohols, using HPAILs as catalysts and NaNO 3 as an oxidant under MW and solvent-free conditions ( Scheme 1 ).…”