Angewandte Chemie International Edition · 2019 · 34 citations · 25 references
Natural SciencesChemical EngineeringChemistryCatalysisGreen ChemistryOrganic ChemistryBio-based MaterialsCatalyst PreparationCatalytic MaterialsProcess SynthesisAmination ReactionsCatalyst ActivityGas Phase OxidationGas-phase ReactionsHydroformylationSolid-phase Catalyst SynthesisStereoselective Amination
as a solid acid catalyst in the ring-opening of biobased γ-valerolactone with methanol in the gas phase leads to mixtures of methyl 2-, 3-, and 4-pentenoate (MP) in over 95 % selectivity, containing a surprising 81 % of M4P. This process allows the application of a selective hydroformylation to this mixture to convert M4P into methyl 5-formyl-valerate (M5FV) with 90 % selectivity. The other isomers remain unreacted. Reductive amination of M5FV and ring-closure to ϵ-caprolactam in excellent yield had been reported before. The remaining mixture of 2- and 3-MP was subjected to an isomerising methoxycarbonylation to dimethyl adipate in 91 % yield.
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