Hydrothermal synthesis of γ-MnOOH nanowires using sapless leaves as the reductant: an effective catalyst for the regio-specific epoxidation of β-ionone

An increasing number of nanomaterials have been regarded as effective catalysts for different organic reactions due to their controlled morphologies, large lattice planes and high specific surface area. Among them, gamma-MnOOH nanowires were successfully fabricated via a simple hydrothermal approach with sapless leaves as a high-efficiency reductant. The as-prepared material was found to be an effective catalyst for the regio-specific epoxidation of beta-ionone to produce (E)-4-(2,2,6-trimethyl-7-oxabicyclo[4.1.0]heptan-1-yl)but-3-en-2-one, which is a key intermediate in the spice industry, and for the total synthesis of the growth hormone of plants, namely abscisic acid. In this gamma-MnOOH nanowire-catalysed reaction, O-2 was used as a cheap, clean and safe oxidant, and the yield could be up to 50%. These findings can not only provide a controlled and green route for the fabrication of gamma-MnOOH nanowires, but also indicate new progress in the field of highly selective beta-ionone epoxidation.