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OtherMisc.Oxid.

VIII.4OtherMiscellaneous

Palladium-Catalyzedor-Promoted

OxidationReactions

EI-ICHINEGISHI

A.INTRODUCTION

InadditiontovariousPd-catalyzedor-promotedoxidationreactionsdiscussedinearlier

parts,forexample,PartV,andtheprecedingsectionsinthispart,therearemanyother

typesofoxidationreactions.Somemayberelatedtothosediscussedearlier.Andyet,

theydisplaysomenotablydifferentfeatures.Inthissection,severaldifferenttypesof

suchoxidationreactionsarediscussedinnoparticularorder.Moreover,thefollowing

discussionisbynomeanhaustive,anditisverylikelythatmanyadditionaltypesof

oxidationreactions,whichdonotbelongtoanygroupofoxidationreactionsdiscussedin

thisHandbook,willbediscoveredinthefuture:

1.Oxidationviachelation-assistedareneC—Hactivation.

2.OxidationinvolvingunassistedalkaneC—Hactivation.

3.Wacker-typeoxidationreactionsinvolvingrearrangements.

4.OxidationinvolvingC—Cbondcleavageandformationotherthancouplingof

organometals(Sect.III.2.20)orhydrocarbons(Sect.VIII.2).

B.PALLADIUM-CATALYZEDOR-PROMOTEDOXIDATION

OFARENESVIACHELATION-ASSISTEDARENEC—HACTIVATION

ThestrictlyregioselectivepalladationtogivepalladacyclesshowninScheme4ofthe

precedingsection(Sect.VIII.3.3)mustundoubtedlybechelation-assisted.Althoughitis

notfullyclearwhetherthereactionadditionallyinvolves-complexationasshownin

Scheme3ofSect.VIII.3.3,suchaninteractionwouldinvolveconsiderablestrainand

henceisunlikelybesidesbeingunnecessary.Onemaythereforeconsiderthatthechela-

tion-assistedC—Hactivationisaprocessinvolving,inthemain,only-bonds.

AvarietyofLewis-basicnonbondingelectrondonors