Iridium-Catalyzed Allylation of Amines by Allylic Alcohols or Ethers

摘要

π-Allyliridium(HI) complexes have usually been prepared from iridium(I) complexes such as [IrCl(cod)]2 and allylic esters such as allylic acetates and carbonates to undergo nucleophilic substitutions. We have found that tin(II) chloride mediates the formation of π-allyliridium complex from allyl alcohol to cause a nucleophilic addition to carbonyl compounds, namely a carbonyl allylation, whereas without addition of the carbonyl compounds the π-allyliridium complex serves as an electrophile to undergo a nucleophilic substitution with allyl alcohol. Thus, these results suggested the amphotericity of the π-allyliridium complex and the equilibrium between allylic ether and π-allyliridium alkoxide, and the amphotericity and the equilibrium were applied to an iridium-catalyzed allylic etherification with alkanols and an iridium-catalyzed carbonyl allylation with allylic ethers. We here report on availability of the π-allyliridium complex as a electrophile; a nucleophilic substitution of amines to the π-allyliridium complexes prepared from allylic alcohols or ethers with tin(II) chloride.