Intramolecular Alkene Aminopalladation Reactions of (dppf)Pd(Ar)[N(Ar1)(CH2)3CH═CH2] Complexes. Insertion of Unactivated Alkenes into Pd−N Bonds

摘要

The prospect of effecting syn-migratory insertion of alkenes intonpalladium nitrogen bonds has been of longstanding interest innorganometallic chemistry. Studies on the viability of this transformationnwere a focal point of early work toward the development of late-metalncatalyzed hydroamination reactions.n1,2nHowever, a number of experi-nments suggested that aminopalladation reactions of alkenes generallynproceed through outer-sphere anti-addition pathways.n3nMore recently,nthe syn-insertion of alkenes into Pd N bonds has been implicated asna key step in many useful Pd-catalyzed reactions including alkenencarboaminations,n4ndiaminations,n5noxidative aminations,n6nchloroami-nnations,n7naminoacetoxylations,n8nand hetero-Heck transformations.n9,10nHowever, despite the considerable interest in these processes, the syn-nmigratory insertion of an alkene into the Pd N bond of a well-ncharacterized palladium amido complex has yet to be observed.