Periodic Reporting for period 3 - Foldmetcat (Bioinspired Catalytic Metallofoldamers)
Reporting period: 2022-09-01 to 2024-02-29
Our goal, inspired by mimicking the characteristics of terpenoid cyclase enzymes, is unprecedented, although it is rooted on fundamental organometallic chemistry. Although our most of work will be carried out with gold catalysts, another goal of this research is to develop other general-purpose efficient chiral electrophilic catalysts based on different metals.
A new family of catalysts with ligands bearing urea, thiourea, and squaramide subunits have been designed for the silver-free gold-catalyzed enantioselective folding of unsaturated substrates. This has led to the development of the new concept of H‑bonded counterion-directed enantioselective gold(I) catalysis.
Small gold(I) and gold(I)-silver(I) clusters have also been synthesized for the activation of alkynes. We have also studied alternative catalysts based on metals different from gold (such as rhodium and zinc). In particular, Rh(II) salts have found to be highly reactive for the generation of the corresponding metal carbenes by decarbenation of substituted cycloheptatrienes.
We have also discovered the activation of acetylene gas catalyzed by gold and have studied the oligomerization of acetylene under mild conditions as well as other metathesis-type reactions with electron-rich alkenes. In these transformations, acetylene behaves as a C2 dicarbene unit leading to double cyclopropanations. This method was applied for the first total synthesis of waitziacuminone, which was remarkably completed in a single step, as well as for the synthesis of chromanes by intermolecular aryloxyvinylation with acetylene gas.