New cyclic chiral pseudo-peptides as organocatalysts.
In: Abstracts of Papers, 229th ACS National Meeting, San Diego, CA, United States, March 13-17, 2005
San Diego (2005), S. ORGN-763
Buchaufsatz / Kapitel / Fach: Chemie
The last few years have witnessed a spectacular advancement in new catalytic methods based on metal-free org. mols. In many cases, these small compds. give rise to extremely high enantioselectivitys. Chiral amines play a main role in this expanding area. Recent studies have shown that org. catalysts bearing chiral cyclic amines such as proline-derived compds. and modified chinchona alkaloids are promising catalysts. We describe the synthesis of new pseudo-peptidic chiral platforms as organocatalysts which are derived from natural amino acids. The presence of three five-membered heteroarom. rings leads to a rigid scaffold. Different functional groups (R1-4) are introduced to tune the catalytic activity of the platform. We expect to catalyze enantioselectively reactions using these platforms as chiral Lewis-base/nucleophilic catalysts. In studies, we carried out on the 1,4-addn. of thiols to cyclic enones, org. asym. catalysis by our compds. was obsd. Recently we have been working on the development of new pseudo-peptidic platform-catalyzed enantioselective reactions.