Synthesis of Bicyclic Enediynes fromBis[phenyl[(trifluoromethanesulfonyl)oxy]iodo]acetylene: ATandem Diels−Alder/Palladium(II)- and Copper(I)-CocatalyzedCross-Coupling Approach
The reaction of bicycloalkenylbis(phenyliodonium) triflates1a or b (available via theDiels−Alderreaction ofbis[phenyl[(trifluoromethanesulfonyl)oxy]iodo]acetylenewith cyclopentadiene or furan,respectively) with alkynylstannanes2a−g at room temperature in DMF inthe presence of catalyticamounts oftrans-benzyl(chloro)bis(triphenylphosphine)palladium(II)and copper(I) iodide proceedssmoothly and with selectivity to afford good to excellent yields ofbicyclic enediynes3a−k.