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Bioinspired Catalytic Metallofoldamers

Periodic Reporting for period 1 - Foldmetcat (Bioinspired Catalytic Metallofoldamers)

Reporting period: 2019-09-01 to 2021-02-28

The goal of this proposal is to design new types of catalysts containing electrophilic transition metal centers that could simultaneously fold and activate polyunsaturated substrates promoting non-inherent cyclization modes. 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, a goal of this research is to develop other general-purpose efficient chiral electrophilic catalysts based on different metals.
A significant part of the research work has been focused on the design and synthesis of second-generation catalysts based on Johnphos ligands modified with a C2-chiral pyrrolidine subunit as well as related complexes based on chiral planar ferrocene ligands. These catalysts have allowed to develop an atroposelective synthesis of aryl-substituted indole derivatives. A new family of catalysts with ligands bearing urea, thiourea, and squaramide subunits have been developed for the silver-free gold-catalyzed activation of alkynes and the enantioselective folding of unsaturated substrates. 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), along the goals of the.
We have also reported the first activation of acetylene gas catalyzed by gold and are now studying the oligomerization and polymerization acetylene gas under very mild conditions as well as other reactions of simple acetylenes. Finally, new digold chiral cavitand complexes have been developed and other bimetallic catalysts (Au/Cu, Au/Ru) are under development.
Our new mononuclear gold catalysts (with Johnphos ligands modified with a C2-chiral pyrrolidine subunit, chiral planar ferrocene ligands) and cavitad digold, based on new designs, lead to the highest enantioselectivities observed thus far in some cyclization and cycloaddition reactions.
Cationic Gold(I)-Cavitand Catalysts. Aplication in total synthesis of carbaxole alkaloids
Enantioselectiuve folding of enynes with pyrrolidinylbiphenylphosphine Au Catalysis