Mild Deoxygenation of Aromatic Ketones and Aldehydes over Pd/C Using Polymethylhydrosiloxane as the Reducing Agent

Abstract

Herein, a practical and mild method for the deoxygenation of a wide range of benzylic aldehydes and ketones is described, which utilizes heterogeneous Pd/C as the catalyst together with the green hydride source, polymethylhydrosiloxane. The developed catalytic protocol is scalable and robust, as exemplified by the deoxygenation of ethyl vanillin, which was performed on a 30 mmol scale in an open-to-air setup using only 0.085 mol % Pd/C catalyst to furnish the corresponding deoxygenated product in 93 % yield within 3 hours at room temperature. Furthermore, the Pd/C catalyst was shown to be recyclable up to 6 times without any observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions.

Synthesis and Derivatization of 3‐Aroyl Pyroglutamic Acids

“…A possible explanation for this might be the stability of conformation involving intramolecular hydrogen bond between the free hydroxy group at C‐3 and carbonyl functionality. The best diastereoselectivity was achieved using poly(methylhydrosiloxane) as a reducing agent with palladium catalyst (entry 5). The desired hydroxy derivate 12 a was isolated in 78 % yield and excellent diastereoselectivity 97 : 3.…”

Carbon‐Based Material‐Supported Palladium Nanocatalysts in Coupling Reactions: Discussion on their Stability and Heterogeneity

“…The application of CBMs in heterogeneous catalysis has a long history because they can satisfy most of the desirable characteristics required for excellent support . Recently, due to the large specific surface area, chemical stability, easy recyclability and electronic conductivity of CBMs, they have been widely used as catalyst supports for organic synthesis and electrocatalysis …”

Pd Nanoparticles Decorated on Hypercrosslinked Microporous Polymer: A Highly Efficient Catalyst for the Formylation of Amines through Carbon Dioxide Fixation

“…Recently, synthesis of formamides from amines by CO 2 fixation using hydrosilane or molecular hydrogen as the hydrogen source has been reported. However, utilization of H 2 as a reducing agent required harsh reaction conditions compared with hydrosilanes.…”