One-Pot Three-Component Synthesis of Highly Substituted Piperidines Using 1-Methyl-2-Oxopyrrolidinium Hydrogen Sulfate

Abstract

1-Methyl-2-oxopyrrolidinium hydrogen sulfate ([Hpyro][HSO 4 ]) is used as an ionic liquid catalyst for the one-pot three-component synthesis of highly substituted piperidines from aromatic aldehydes, anilines and β-ketoesters in refluxing ethanol. This homogeneous catalyst procedure has the advantages of easy work-up, no need for column chromatography, simple and readily available precursors, and good to high yields.

One‐Pot Pseudo Five Component Synthesis of Biologically Relevant 1,2,6‐Triaryl‐4‐arylamino‐piperidine‐3‐ene‐3‐ carboxylates: A Decade Update

“…Ionic liquid 1‐methyl‐2‐oxopyrrolidinium hydrogen sulfate ([Hpyro][HSO 4 ]) efficiently catalyzed the one‐pot pseudo five‐component reactions of various aromatic aldehydes, anilines and β‐ketoesters to afford the corresponding highly substituted functionalized piperidines in ethanol under reflux condition (Scheme ) …”

Multi-component synthesis of piperidines and dihydropyrrol-2-one derivatives catalyzed by a dual-functional ionic liquid

“…12 Recently, multicomponent reactions (MCRs) have been employed for the synthesis of substituted piperidines. [13][14][15][16][17][18][19][20][21][22] In addition, dihydropyrrol-2-ones are important in organic synthesis due to their wide spectrum of activity which includes anti-microbiological, 23,24 antitumor, 25,26 anti-inflammatory, 27 antimalarial, 28 antifungal, 29 antidiabetics, 30 and antibiotic properties. 31 Therefore, many methodologies have been developed to synthesize these practical heterocycles.…”

Ruthenium Chloride Catalysed Multicomponent Reaction for Efficient and One-Pot Synthesis of Functionalised Tetrahydropiperidines at Room Temperature

“…[4][5][6] Compounds containing piperidines exhibit diverse biological activities including anti-hypertensive, 7 anti-bacterial, 8 anticonvulsant, anti-inflammatory 9 and antimalarial. 10 In recent years, several methods have been reported for the synthesis of functionalised piperidines in the presence of various catalyst such as InCl 3 , 11 L-proline/TFA, 10 tetrabutylammonium tribromide (TBATB), 5 1-methyl-2-oxopyrrolidinium hydrogen sulfate ([Hpyro][HSO 4 ]), 12 ZrOCl 2 .8H 2 O, 13 Bi(NO 3 ) 3 .5H 2 O, 14 trityl chloride (Ph 3 CCl), 15 cerium ammonium nitrate (CAN), 16 Y(NO 3 ) 3 •4H 2 O, 17 Ce(OTf) 4 , 18 and FeCl 3 /SiO 2 NPs. 19 Despite the large number of developed catalysts for this reaction, many of these methods suffer from disadvantages such as long reaction times, low yields, expensive catalysts, tedious work-up procedures and the requirement of harsh reaction conditions such as strong acids or elevated temperature.…”