Oxygen Palladium dichloride

A very few examples of the use of aryl-tin,21 -lead,21 -lithium43 and -magnesium21143,44 derivatives as the source of the aryl group in vinyl substitutions have been reported. Tin derivatives have been used with palladium dichloride bis(benzonitrile) and a copper(II) chloride reoxidant in a regioselective synthesis of oxygen heterocycles from unsaturated alcohols.43... 

Cuprous chloride CuCl (mp 430 °C), when complexed with amines such as pyridine or phenanthroline, catalyzes the oxidation of alcohols to aldehydes and ketones by air [347]. In the presence of palladium dichloride, l dCl2, in aqueous dimethylformamide, terminal alkenes are converted by oxygen into methyl ketones [348],... 

The second example involves the kinetic resolution of racemic secondary alcohols, a process that also has been used in a total synthesis. As illustrated in Figure 14.27, the naturally occurring tricyclic diamine sparteine, in combination with palladium dichloride and oxygen as the terminal oxidant, catalyzes the oxidation of one enantiomer of the race mic benzylic alcohol to the ketone faster than it oxidizes the other enantiomer. The desired unreacted alcohol was isolated in 47% yield with 99% ee (s > 47) and was subsequently transformed to (+)-amurensinine. ... 

Di-2-pyridyl thionocarbonate, 127 Formaldehyde, 136 Iodomethyltrimethylsilane, 315 Palladium(II) acetate, 232 Tributyl(iodomethyl)tin, 314 Ene reaction Ethylaluminum dichloride, 5 Oxygen, singlet, 228 8-Phenylmenthol, 243 Zinc bromide, 349 Enol acylation... 

Miscellaneous Oxidation Reactions. The kinetic resolution of secondary alcohols is achieved by a palladium-catalyzed enan-tioselective oxidation using Pd[(—)-sparteine]Br2/(—(-sparteine or Pd(CH3CN)2(Br)2/chiral diamine sparteine mimic under an oxygen atmosphere. The chiral amine-dibromide complexes are observed to oxidize secondary alcohols more rapidly than the dichloride complexes (eq 7). This has been attributed to a greater counterion distortion from ideal square planar geometry, which could lower the energy barrier to 8-hydride elimination. 

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