Gold(I)-Catalyzed Reaction of Ferrocene and Propargylic Esters: Synthesis of Functionalized Ferrocene Derivatives

The reaction of propargylic esters with ferrocene in the presence of gold catalysts provided ferrocene derivatives containing a functionalized vinyl moiety. This ferrocene C–H bond functionalization proceeded with complete regio- and stereoselectivity. The reaction was proposed to proceed through electrophilic substitution, in which a vinylgold carbene intermediate arising from 1,2-rearrangement of the starting propargylic ester would behave as the electrophilic counterpart.