Oxygenolysis

As a general summary, three principal gasification reactions of carbon from coal are oxygenolysis, hydrogenolysis, and hydrolysis. These reactions are shown by the following simplified examples ... 

Cobaltn-Schiff base complexes, e.g. Co(salen),567 Co(acacen)568 and cobalt(II) porphyrins,569 e.g. Co(TPP), are effective catalysts for the selective oxygenation of 3-substituted indoles to keto amides (equation 249), a reaction which can be considered as a model for the heme-containing enzyme tryptophan-2,3-dioxygenase (equation 21).66 This reaction has been shown to proceed via a ternary complex, Co-02-indole, with probable structure (175), which is converted into indolenyl hydroperoxide (176). Decomposition of (176) to the keto amide (174) readily occurs in the presence of Co(TPP), presumably via formation of a dioxetane intermediate (177).569,56 Catalytic oxygenolysis of flavonols readily occurs in the presence of Co(salen) and involves a loss of one mole of CO (equation 251).570... 

Dual oxygenolysis (rupture of C-Cand C-H to give C02and H2O)... 

Scheme 7. Partial synthesis of the elusive red chlorophyll catabolite (RCC, 11) from pheophorbide a (5a). Photo-oxygenolysis of Cd-methyl-pheophorbidate a (Cd-13) gave Cd-methyl-4,5-dioxo-4,5-secopheophorbidate a (14) (besides a trace of the isomeric Cd-methyl-19,20-dioxo-19,20-seco-pheophorbidate, Cd-15) reduction of 14 with sodium borohydride and metal extrusion with dilute aqueous acid provided mcthyl-4,5-dioxo-4,5-seco-pheophorbidate 16 in good yield partial hydrolysis of the red diester 16 with pig liver esterase was regio-selective and produced red chlorophyll catabolite 11 (RCC)...

Indeed, recent studies by Kishi and coworkers on the photo-oxygenolysis of the 20-methoxy-pyropheophorbide 35 have confirmed the assumed tendency of such substituted pheophorbides (see e.g. (75)) to undergo oxygenolytic cleavage of the chlorin macro-ring at the western mew-position, between C(20) and C(l), and providing synthetic access to the 1,20-seco-pyropheophorbidate 36 (see Scheme 17) (77). 

Pll. Pitt, B. M., A model for oxygenase reactions. The oxygenolysis of aryl pyruvates to aromatic aldehydes and oxalate. Abstr. Am. Chem. Soc. 138th Meeting pp. 7C-8C (1960). 

RogkS, M. M., T. R. Demmin, and W. B. Hammond Cleavage of Carbon-Carbon Bonds. Copper(II)-Induced Oxygenolysis of o-Quinones, Catechols and Phenols. J. Amer. Chem. Soc. 98, 7441 (1976). 

The term steam reforming should not be confused with catalytic reforming used for the conversion of paraffinic hydrocarbons to high octane hydrocarbons such as iso-alkanes and aromatics. A better term may be oxygenolysis [381] [389] as the reaction involves the breakage of C-H and C-C bonds by means of oxygen containing species. 

Hydrocarbons such as methane are not the only fuels suitable for steam reforming. Alcohols will also react in an oxygenolysis or steam reforming reaction, for example, methanol... 

The role of oxygen in the copper(n)-induced oxygenolysis of o-quinones, catechols, and phenols has been re-assessed. Contrary to previous proposals, it appears that the role of O 2 is to re-oxidize the Cu generated in the course of the reaction between catechol and the Cu i oxidant present initially. 

Scheme 2. Mechanism for oxygenolysis of 4-methylindole by cobalt schiff base complexes [23].

Scheme 14. Mechanism of the oxygenolysis of nitroalkanes via a hydroperoxide interemediate [75].

Chen et al. showed that deltamethrin was degraded by hydrolysis of the carboxylic ester bond to prodnce a-hydroxy-3-phenoxy-benzeneacetonitrile and 3-phenoxybenzaldehyde. These intermediates were degraded by oxygenolysis to form 2-hydroxy-4-methoxybenzophenone and 1,2-benzenedicarboxylic acid mono esters, finally resnlting in complete detoxication (Chen et al. 2011c). 

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