Tandem metal relay catalysis: from cyclopropene to polysubstituted furan.

Transmetalation is a key step in traditional coupling reactions. Herein we discuss the most recent progress in the metal-metal relay catalysis based on a transmetalation strategy. An efficient synthetic strategy for the formation of polysubstituted furan derivatives from cyclopropenes based on the tandem metal relay catalysis (TMRC reaction) is summarized.

Modular synthesis of all-substituted furans through oxidative carbonylation of cyclopropenes with tandem metal relay catalysis.

A modular synthesis of tetrasubstituted furan carboxylates using a tandem cycloisomerization/oxidative carbonylation sequence of cyclopropenes has been successfully developed. The Tandem Metal Relay Catalysis (TMRC) pathway accounted for the high efficiency of this transformation.

Cu/Pd-Catalyzed, Three-Component Click Reaction of Azide, Alkyne, and Aryl Halide: One-Pot Strategy toward Trisubstituted Triazoles.

A Cu/Pd-catalyzed, three-component click reaction of azide, alkyne, and aryl halide has been developed. By using this Cu/Pd transmetalation relay catalysis, a variety of 1,4,5-trisubstituted 1,2,3-triazoles were quickly assembled in one step in high yields with complete regioselectivity, just like assembling Lego bricks. Notably, different from the well-established CuAAC click reactions only working on terminal alkynes, this reaction offers an alternative solution for the problem of the click reaction of internal alkynes.

Dimerization of cyclopropenes to bifurans using tandem metal relay catalysis.

An efficient synthesis of bifurans via dimerization of cyclopropenes has been successfully developed using a copper-promoted cycloisomerization and palladium-catalyzed dimerization cascade. These novel bifuran structures possess interesting optoelectronic properties.