Oxidation RuCl2 3-catalyzed

Figure 9.4 Aerobic oxidation of primary and secondary alcohols catalyzed by RuCl2 (Ph3P)3/TEMPO in PhCl at 100°C.

Quinolines can be prepared from the oxidative coupling and cyclation of the 2-aminobenzyl alcohol and ketones (Scheme 4) catalyzed by the system [RhCl(PPh3)3]/KOH [58]. The reactions were carried out in dioxane at 80 °C with 85% yield in 24 h (alcohol/Rh = 100/1). However, better yields are obtained with the related ruthenium system [RuCl2(=CHPh)(PCy3)2 [59]. 

Oxidative cyclization of benzyl and other 2-hydroxyethyl ethers to afford dioxolanes (Equation 46) can be achieved using A -iodosuccinimide in nitromethane for R = Ph <1998AGE3177> or photochemical reaction with iodine and polymer-supported iodobenzene diacetate in acetonitrile <2005SL923>. In a related process, RuCl2(Ph3P)2 catalyzes the isomerization of allyl 2-hydroxyethyl ether to form 2-ethyl-l,3-dioxolane <2004SL1203>. 

Decarbonylation of acyl cyanides- Aromatic acyl cyanides, which are easily obtained by oxidation of cyanohydrins with r-butyl hydroperoxide catalyzed by RuCl2[P(C6H5)3]3, undergo decarbonylation to nitriles in high yield when heated in the presence of Pd(0). 

One of us has developed [8] a mild aerobic oxidation of alcohols, catalyzed by RuCl2(PPh3)3 and a macrocyclic metal complex ( Scheme 1). 

SUanols Autoxidation of silanes in the air is catalyzed by [(p-cymene)RuCl2]2-This oxidation, which gives silanols of inverted configuration, is amenable to large-scale production. 

Oxidation. The presence of TEMPO is essential to the smooth autoxidation of primary alcohols to aldehydes catalyzed by (PhiP),RuCl2. Without TEMPO, further conversion of the aldehydes to carboxylic acids is observed. 

Acylcyanides. The oxidation of cyanohydrins with t-BuOOH to furnish acyl-cyanides is catalyzed by (PPhj),RuCl2. The products can be used for selective N-acylation of amino alcohols and polyamines. 

Aerobic oxidation of alkanes. Various metal complexes are known to catalyze air oxidation of unactivated C—H bonds. Murahashi el al. have found that both ruthenium and iron complexes are useful catalysts for aerobic oxidation in combination with an aldehyde and an acid. Iron powder is the most effective catalyst, but FeCIs 6H2O, RuCb H2O, and RuCl2[P(C5Hs)3]3 can be used. Useful aldehydes are heptanal, 2-methylpropanal, and even acetaldehyde. A weak acid is suitable thus acetic acid is preferred to chloroacetic acid. By using the most satisfactory conditions, cyclohexane... 

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