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One‐Pot Selective Catalytic Synthesis of Pyrrolidone Derivatives from Ethyl Levulinate and Nitro Compounds
Author(s) -
Vidal Juan D.,
Climent Maria J.,
Corma Avelino,
Concepcion Dr Patricia,
Iborra Sara
Publication year - 2017
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201601333
Subject(s) - chemistry , catalysis , bifunctional , nitro , amination , imine , solvent , reductive amination , bifunctional catalyst , organic chemistry , combinatorial chemistry , alkyl
Abstract N ‐substituted 5‐methyl‐2‐pyrrolidones were prepared in a one‐pot process starting from ethyl levulinate and nitro compounds in the presence of a nanosized Pt‐based catalyst. Pt supported on TiO 2 nanotubes (Pt/TiO 2 ‐NT) catalyzed the synthesis of N ‐substituted 5‐methyl‐2‐pyrrolidones through a cascade process involving the reduction of nitro compounds, formation of the intermediary imine, hydrogenation, and subsequent cyclization. A bifunctional metal–acid system was a suitable catalyst for the process. Pt supported on TiO 2 showed lower catalytic activity than Pt/TiO 2 ‐NT owing to the strong adsorption of nitro compounds during the first reaction step that poisoned the acidic sites and strongly decreased the rate of amination and cyclization. However, Pt/TiO 2 ‐NT with milder acid sites was less affected by the adsorption of nitro compounds and the full cascade process could proceed. The results indicate that the prepared Pt/TiO 2 ‐NT is a chemoselective and reusable catalyst that can be applied to the synthesis of a variety of N ‐substituted 5‐methyl‐2‐pyrrolidones starting from nitro compounds with excellent yields in absence of an additional organic solvent under mild reaction conditions.