The reactivity of 4-hydroxy- and 4-silyloxy-1,5-allenynes with homogeneous gold(I) catalysts.
Two new gold(I)-catalyzed cascade reactions of 4-hydroxy- and 4-silyloxy-1,5-allenynes are disclosed, offering access to a variety of mono- and bicyclic, polyunsaturated carbonyl compounds. The diverse reactivity observed for the investigated allenyne system is controlled by the nature of the unsaturated substrate: Allenynes bearing a free hydroxyl group engage in what is likely an oxycyclization/allene-ene carbocyclization cascade, while their silylated analogues are converted through a carbocyclization/pinacol-type rearrangement process.
Organic Chemistry, Bergische Universität Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany.
Michael
M
Wegener
Organic Chemistry, Bergische Universität Wuppertal, Gaußstr. 20, 42119 Wuppertal, Germany.
Stefan F
SF
Kirsch