Gold(i) catalyses the ring-opening addition of cyclopropenes in a mild and regioselective manner.

Gold(I)-catalysed reaction between cyclopropenes and furans produces functionalised conjugated trienes. The reaction is mild, facile and proceeds with very low catalyst loadings.

Gold(i)-catalysed addition of alcohols to 3,3-disubstituted cyclopropenes occurs in a highly regioselective and facile manner to produce alkyl tert-allylic ethers in good yields. The reaction is tolerant of sterically hindered substituents on the cyclopropene as well as primary and secondary alcohols as nucleophiles. In this full article, we report on the substrate scope and plausible mechanism, as well as the regioselectivity issues arising from subsequent gold(i)-catalysed isomerisation of tertiary to primary allylic ethers.

A highly regioselective method towards tertiary allylic ethers via gold(I)-catalyzed intermolecular hydroalkoxylation of allenes is disclosed. Preventing subsequent isomerization of the tertiary allylic ether products to primary allylic ethers appears to be the key to achieving high regioselectivities.

Depending on the conditions employed, gold(I)-catalyzed addition of indoles to 3,3-disubstituted cyclopropenes can be controlled to yield either 3-(E)-vinylindoles (3) or bis-indolylalkanes (4). If the cyclopropene substituents are sterically bulky, unprecedented gold-catalyzed oxidation under air occurs to yield bis-indolylalkene (5) and epoxide (6) at room temperature.