A Mild TEMPO‐Catalyzed Aerobic Oxidative Conversion of Aldehydes into Nitriles

Fang, Chaojie; Li, Meichao; Hu, Xinquan; Mo, Weimin; Hu, Baoxiang; Sun, Nan; Jin, Liqun; Shen, Zhenlu

doi:10.1002/adsc.201501130

Cited by 50 publications

(19 citation statements)

References 62 publications

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“…Recently, several metal‐free catalytic systems have been developed for the synthesis of nitriles by the oxidative cyanation of aldehydes [11] . Nevertheless, these reported systems were homogeneous catalysts (i.e., nitroxyl/NO x , [11a] and modified TEMPOs [11b–e] ) or special nitrogen resource (hydroxylamine‐ O ‐sulfonic acid [11f] ). Undoubtedly, from the economical and practical perspective, developing robust, low‐cost, and heterogeneous metal‐free catalysts for direct oxidative cyanation of aldehydes is highly desirable.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

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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.

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Section: Introductionmentioning

confidence: 99%

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

et al. 2021

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“…Some one‐pot syntheses based on the dehydration of aldoximes, obtained in situ from their aldehydes, have also been described. In particular, a dehydration with HMDS and DBU, [11] the use of ethyl chlorophosphates [12] or acid‐catalyzed dehydration in DMSO [13] were reported.…”

Section: Introductionmentioning

confidence: 99%

Process Development of the Copper(II)‐Catalyzed Dehydration of a Chiral Aldoxime and Rational Selection of the Co‐Substrate

Nonnhoff

Gröger

2021

ChemistryOpen

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The access towards chiral nitriles remains crucial in the synthesis of several pharmaceuticals. One approach is based on metal‐catalyzed dehydration of chiral aldoximes, which are generated from chiral pool‐derived aldehydes as substrates, and the use of a cheap and readily available nitrile as co‐substrate and water acceptor. Dehydration of N ‐acyl α‐amino aldoximes such as N ‐Boc‐ l ‐prolinal oxime catalyzed by copper(II) acetate provides access to the corresponding N ‐acyl α‐amino nitriles, which are substructures of the pharmaceuticals Vildagliptin and Saxagliptin. In this work, a detailed investigation of the formation of the amide as a by‐product at higher substrate loadings is performed. The amide formation depends on the electronic properties of the nitrile co‐substrate. We could identify an acceptor nitrile which completely suppressed amide formation at high substrate loadings of 0.5 m even when being used with only 2 equivalents. In detail, utilization of trichloroacetonitrile as such an acceptor nitrile enabled the synthesis of N ‐Boc‐cyanopyrrolidine in a high yield of 92 % and with full retention of the absolute configuration.

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“…Inspired by hereinbefore work, as a part of our research program aimed at synthesis of nitriles and I 2 -catalyzed reaction, [50][51][52] we attempted to develop a simple, efficient, economical and environmentally friendly method for the direct synthesis of nitriles from aldehydes using NH 4 OAc as the nitrogen source under I 2 /TBHP system (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%