ABSTRACT
Electron transfer is one of the most fundamental and ubiquitous processes of all chemical and biologicalsystems,andthushasbeenstudiedindetailboththeoreticallyandpractically.Inorganic synthesis,electrontransfer-inducedreactionshavebeenextensivelyutilizedtoachievevarious chemicaltransformations,constructingawidevarietyoforganiccompounds,includingnatural products,pharmaceuticalproducts,andfunctionalmaterials.Inordertotriggerelectrontransferinduced reactions, photochemical processes and one-electron redox reagents are widely employed. Inthiscontext,electrochemicalprocesseshavealsobeenutilizedtoregulateeitheroneortwo electrontransfersatthesurfaceoftheelectrodesthataffordnotonlyvariousfunctionalgroup transformationsbutalsoawidevarietyofcarbon-carbonbondformationreactionsinaheterogeneousmanner[1-3].Severalreactiveintermediatessuchasions,radicals,andradicalionsare
I. Introduction ........................................................................................................................... 531 II.Oxidative Mediators .............................................................................................................. 534
A.General Mechanism ....................................................................................................... 534 B.Triarylamines ................................................................................................................. 534 C.TEMPO ......................................................................................................................... 538 D. Halide Ions ..................................................................................................................... 538 E.Iodoarenes ...................................................................................................................... 539 F.o-Aminophenols ............................................................................................................ 543
III.Reductive Mediators ..............................................................................................................544 A.General Mechanism .......................................................................................................544 B. Nickel(II) Salens ............................................................................................................544 C.o-Carboranes ................................................................................................................. 545
IV.Oxidative Chain Reactions ....................................................................................................546 A.General Mechanism .......................................................................................................546 B.Radical Cation Chain Reaction ..................................................................................... 547 C. Cation Chain Reaction ................................................................................................... 547
V.Reductive Chain Reactions ................................................................................................... 549 A.General Mechanism ....................................................................................................... 549 B.Electrochemical SRN1 Reaction ..................................................................................... 550
VI.Measuring Redox Potentials.................................................................................................. 551 A.General Aspects ............................................................................................................. 551 B.Direct Measuring ........................................................................................................... 551 C.Indirect Measuring ........................................................................................................ 551
VII. Conclusions ........................................................................................................................... 552 References ...................................................................................................................................... 553
generated through the electron transfer to avoid consumption of additional redox reagents and the redoxpotentialscanbeeasilycontrolledundermildelectrolyticconditions.Therefore,theyare promising methodologies from an environmental viewpoint.
