ETHYLENE-ASSISTED ALLYLIC CARBON HYDROGEN-BOND ACTIVATION OF SUBSTITUTED ALKENES WITH USE OF DICATIONIC IRIDIUM COMPLEXES - SYNTHESIS, STRUCTURE, AND CONFIGURATIONAL ISOMERISM OF CATIONIC IRIDIUM ETA-3-ALLYL ETHYLENE COMPLEXES

The use of ethylene as a sterically small, chemically inert “enabling” ligand allows the dicationic complex [Cp*Ir(S)3]2+(OTf-)2 (S = acetone) to mediate the allylic carbon-hydrogen bond activation of substituted olefins, a reaction that fails in the absence of ethylene. This reaction produces the thermodynamically less stable exo isomers; the more stable endo isomers are obtained via isomerization reactions. X-ray crystal structures of one exo and one endo allyl complex are reported. © 1990, American Chemical Society. All rights reserved.