Design and synthesis of a bis(hydroxyphenyl)diamide bearing a pendant thiazolium unit; Application to the catalytic asymmetric intramolecular Stetter reaction

The bis(hydroxyphenyl)diamide architecture constitutes as a privileged ligand that promotes a number of catalytic asymmetric transformations in combination with rare-earth metals. A new diamide analog armed with a carbene catalytic function derived from a thiazolium unit was designed, synthesized, and applied to the catalytic asymmetric intramolecular Stetter reaction. Cooperative work between the carbene function and hydrogen bonding interactions was suggested to give the enantioenriched chroman derivatives.