Aerobic oxidation of primary amines

James et al. reported that aerobic oxidation of primary amines in the presence of a ruthenium porphyrin complex Ru(TMP)(0)2 (TMP = tetramesitylporphyrinato) gives nitriles (100%) (Eq. 3.31) [66]. 

Heterogeneous catalysts such as hydroxyapatite-bound Ru complex [67] and Ru/ AI2O3 [68] can be also used for the aerobic oxidation of primary amines to nitriles (Eqs. 3.32 and 3.33). 

Copper amine oxidase (CAO) enzymes carry out the aerobic oxidation of primary amines to aldehydes (Scheme 14.8a). While copper is present in the active site, substrate oxidation proceeds by an organocatalytic pathway involving an o-quinone cofactor via a transamination mechanism (Scheme 14.8b). 

Scheme 14.8 Copper amine oxidases carry out (a) the aerobic oxidation of primary amines...

Kim J, Stahl SS (2013) Cu/nitroxyl-catalyzed aerobic oxidation of primary amines into nitriles at room temperature. ACS Catal 3(7) 1652-1656... 

The selective aerobic oxidation of primary alcohols to aldehydes, but not secondary alcohols to ketones, is reminiscient of the chemistry catalyzed by the Cu-dependent enzyme, galactose oxidase (39). Similarly, the Cu-binding P-amyloid protein relevant to Alzheimer s disease promotes aerobic oxidation of cholesterol, a primary alcohol (cholesterol oxidase activity) (40). The Cu-dependent amine oxidases catalyze the aerobic oxidation of amines to aldehydes (41), the hydration products of imines. Each of these enzymes that promotes aerobic oxidation of primary alcohols and amines to the same products as Ni(TRISOX) catalyze the net reaction in Equation 1. If the net reactions... 

The oxidative behaviour of the acridinium carbocations 61 was also explored by the group of Lacour in the photoinduced electron transfer reaction [160]. In the amount of 2 mol%, the achiral hindered acridinium salt 61 catalyzed the aerobic photooxidation of the primary benzylic amine to benzylimine in the yield of 74% (Scheme 63). 

Arylacetamides undergo aerial oxidation to yield the corresponding a-keto amides without the need of a transition metal salt. The transformation is carried out in the presence of a base (CS2CO3) and Bu4NBr. Primary amines are converted into oximes in an aerobic oxidation employing l,l-diphenyl-2-picrylhydrazyl (1) and WO3/AI2O3 as catalyst. ... 

In 2016, Xu and coworker reported another TM-fee aerobic Al-alkylation method for anilines, some heteroarylamines, and sulfinamides with alcohols (Scheme 49) [209]. As described in their work, these amines are not effective substrates under anaerobic catalyst-free autocatalyzed conditions, so an oxidant has to be employed to initiate the reaction. Differing from Yao and Zhao s protocol by adding O2 to an argon atmosphere [208], they found that a catalytic amount of air is active enough to initiate the reaction. In addition to primary alcohols, secondary alcohols can also be used as the aUcyl source. In mechanistic studies, the authors observed that primary and secondary alcohols underwent different initiation processes, i.e., primary alcohols require the presence of the amine to facilitate the aerobic oxidation to... 

Aerobic Oxidation RU2 " paddlewheels are known to catalyze the oxidation of alcohols and amines with Oj. Under 1 atm Oj, water-soluble Ru2(p-02CMe)3(p-C03) converts primary and secondary alcohols into tJdehydes and ketones, respectively, in a biphasic water/toluene solution at 80 °C [107]. 

Shun-Yi Wang et al. disclosed a novel synthetic approach toward 1,5-disubstituted 1,2,3-triazoles 141 and 1,4-disubstituted 1,2,3-triazoles 142 by aerobic oxidative cycloaddition of a-chlorotosylhydrazone 140 with primary aryl amine 113 (Scheme 4.57) [56]. Significantly, the reaction proceeded smoothly to alford 1,4-disubstituted 1,2,3-triazoles 142 and 1,5-disubstituted 1,2,3-triazoles 141 under catalyst-free, metal-free, azide-free, and peroxide-free conditions. Strikingly, this transformation provided selective synthesis of both regioisomers of 1,2,3-triazoles. 

Many reports of aerobic alcohol oxidation involve homogeneous Pd- [7] and Ru-based [8] catalysts that are effective with benzylic, allylic, and ahphatic primary and secondary alcohols. These catalysts are often inhibited by coordinating functional groups such as heterocycles, amines, and oxygen- or sulfur-containing moieties and are capable of oxidizing alkenes. Efforts to develop scalable applications of Pd-based catalysts raised concerns about large-scale prospects for these... 

This combination of anaerobic and aerobic environment adds some complexity to the process but enables larger loads to be purified such as shown in Figure 2-23. One of the primary effluent gasses is trimethylamine. This tertiary amine has the very characteristic odor of rotten fish. Combustion methods can be used to treat this waste but these will produce NOj, effluents unless very special measures are employed in waste treatment. An alternative wet chemical processes was developed (Bohrer, 1999). The liquid solution waste can also be oxidized to produce a non-odoriferous solid using hydrogen peroxide. This alternative waste treatment process keeps the nitrogen fixed, reducing the atmospheric... 

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