Combined coinage metal catalysis for the synthesis of bioactive molecules

The use of the coinage metals copper, silver, and gold enables an efficient and stereoselective assembly of bioactive heterocycles via allenic intermediates. Whereas copper is mediating or catalyzing the synthesis of functionalized allenes by SN2′-substitution or SN2′-reduction, silver and gold are the catalysts of choice for subsequent 5- or 6-endo-cyclizations. Overall, this sequence proceeds with efficient center-to-axis-to-center chirality transfer. Recent advances of this combined coinage metal catalysis include the synthesis and transformation of substrates containing two adjacent allenic π-systems or heteroatoms, the development of recyclable gold catalysts, and the combination of two catalytic processes in tandem or one-pot reactions.