Asymmetric Synthesis of O- and N-Heterocycles by Intramolecular Hydroamination and -alkoxylation

Significance

Asymmetric intramolecular hydro­amination, hydroalkoxylation, and hydrocarbonation of alkynes mediated by palladium-(R,R)-re­norphos catalytic systems to form 5- and 6-membered O- and N-heterocycles with and without aromatic ring annulation is reported. Thus, pyrrolidines, piperidines and isoquinolines are obtained in 52-92% yield; tetrahydrofurans, tetrahydropyrans, phthalens and isochromanes are formed under conditions C. Of disadvantage are the high catalytic loading (condition B) and the required ligand equivalents. The absolute configuration was established by transforming the N-phenylethenyl­pyrrolidine and a selected tetrahydrofuran into known derivatives. A mechanism involving a palladium-allyl intermediate was proposed.