Benzoin, catalytic oxidation scheme

Benzo crown ether, 39 115-116 Benzoin, catalytic oxidation scheme, 33 62 Benzonitrile, reaction with hexafluoroacetone, 30 268... 

Fig. 18. Catalytic oxidation scheme of benzoin by 1,4-benzoquinone in the presence of [Fe4S4(SR)4]2- in DMF.

Direct conversion of aldehydes to esters was carried out via oxidative benzoin reactions, using an aromatic nitro compound as an oxidizing agent under the catalytic action of cyanide ion or of a conjugate base of a thiazolium ion (Scheme 9). ... 

In the presence of a catalytic amount of PhsBi, 1,2-glycols are oxidatively cleaved by NBS to afford the corresponding carbonyl compounds (Scheme 14.141) [291]. When treated with a mixture of PhsBi and tBuOOH in CCI4, bibenzyl is oxidized to benzoin in low yield [292]. 

Sequential reactions involving metal and NHC catalysis are quite scarce in the literature NHCs are powerful ligands that coordinate many metals, resulting in altered activities for both partners, so it may be difficult to create balanced catalytic systems. Fortunately, the few examples available cover several NHC mechanistic pathways, including the benzoin condensation [104], homoenolate addition [105], and NHC-catalyzed oxidation [106, 107] (Scheme 26.21). 

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See also in sourсe #XX -- [ ]

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