Highly Efficient Oxidative Cyanation of Aldehydes to Nitriles over Se,S,N‐tri‐Doped Hierarchically Porous Carbon Nanosheets

Abstract

Oxidative cyanation of aldehydes provides a promising strategy for the cyanide‐free synthesis of organic nitriles. Design of robust and cost‐effective catalysts is the key for this route. Herein, we designed a series of Se,S,N‐tri‐doped carbon nanosheets with a hierarchical porous structure (denoted as Se,S,N‐CNs‐x, x represents the pyrolysis temperature). It was found that the obtained Se,S,N‐CNs‐1000 was very selective and efficient for oxidative cyanation of various aldehydes including those containing other oxidizable groups into the corresponding nitriles using ammonia as the nitrogen resource below 100 °C. Detailed investigations revealed that the excellent performance of Se,S,N‐CNs‐1000 originated mainly from the graphitic‐N species with lower electron density and synergistic effect between the Se, S, N, and C in the catalyst. Besides, the hierarchically porous structure could also promote the reaction. Notably, the unique feature of this metal‐free catalyst is that it tolerated other oxidizable groups, and showed no activity on further reaction of the products, thereby resulting in high selectivity. As far as we know, this is the first work for the synthesis of nitriles via oxidative cyanation of aldehydes over heterogeneous metal‐free catalysts.

Direct Oxidative Cyanation of Alcohol to Nitrile over CoOx/MnO2 with Aqueous Ammonia

“…Consequently, cyanide-free synthesis of nitrile is concerned and attempted. Several cyanide-free synthesis methods for nitrile have been developed, such as amide and aldoxime dehydration, alkene gas-phase ammoxidation, and direct oxidative cyanation of alcohol or aldehyde. , Among them, direct oxidative cyanation of alcohol with ammonia is recognized as a green method for the preparation of nitrile for its high reaction efficiency, mild reaction condition, and green byproduct of water.…”

Carbon Materials as Catalytic Tools for Oxidative Dehydrogenations and Couplings in Liquid Phase

“…under O2 pressure (5 bar) at 80 °C utilizing Se,S,N-tri-doped hierarchically porous carbon nanosheets (Scheme 29). 82 The catalytic activity was Template for SYNTHESIS Thieme found to correlate with the amount of heteroatom dopants and the catalyst was shown to retain activity over 5 cycles. Both electron donating and electron withdrawing groups were welltolerated with yields between 75% and 99%.…”

Wavelength-Specific Product Desorption as a Key to Raising Nitrile Yield of Primary Alcohol Ammoxidation over Illuminated Pd Nanoparticles

“…Progress in this direction has been made by using molecular oxygen as the oxidant and conducting the process under mild reaction conditions. Nevertheless, pure O 2 and high reaction temperatures are still required. − These demanding conditions impede adoption of these methods, and the development of greener and safer procedures remains a challenge.…”