Broad scope gold(i)-catalysed polyenyne cyclisations for the formation of up to four carbon-carbon bonds

Abstract

The polycyclisation of polyenynes catalyzed by gold(i) has been extended for the first time to the simultaneous formation of up to four carbon-carbon bonds, leading to steroid-like molecules with high stereoselectivity in a single step with low catalyst loadings. In addition to terminal alkynes, bromoalkynes can also be used as initiators of polyene cyclisations, giving rise to synthetically useful cyclic bromoalkenes.