A copper-catalyzed difunctionalizing trifluoromethylation of activated alkynes with the cheap reagent sodium trifluoromethanesulfinate (NaSO₂CF₃ or Langlois’ reagent) has been developed incorporating a tandem cyclization/dearomatization process. This strategy affords a straightforward route to synthesis of 3-(trifluoromethyl)-spiro[4.5]trienones, and presents an example of difunctionalization of alkynes for simultaneous formation of two carbon–carbon single bonds and one carbon–oxygen double bond.

A novel copper-catalyzed one-pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF₃-containing 3-butenal or 3-buten-1-one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4-aryl migration proceeds through a radical pathway.

A novel copper-catalyzed one-pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF₃-containing 3-butenal or 3-buten-1-one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4-aryl migration proceeds through a radical pathway.

An efficient copper catalysis system for the chloroamination of alkynes with chlorosulfonamide at room temperature is described, providing a highly regio- and stereoselective procedure for the synthesis of (E)-β-chloro-enesulfonamides in moderate to good yields.

The electrophilic cyclization of various propargylic oxirane compounds and I₂ offers an efficient and straightforward route to highly substituted iodofurans under mild reaction conditions. Further functionalization has demonstrated that the iodo derivatives obtained are potential synthetic intermediates for the amplification of molecular complexity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)