Metal Catalyzed 1,2-Amino-Alcohol & Diamine Synthesis

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DESCRIPTION (provided by applicant): Vicinal amino-alcohols and diamines are an important class of compounds that are difficult to access in rapid and enantioselective fashion. The recently discovered insertion of imidozirconium complexes into epoxides holds promise for the development of a direct and stereo-controlled method to access these compounds. The proposed study examines the scope and mechanism of this novel insertion reaction, with the goal of developing a new catalytic asymmetric synthesis of both vicinal amino-alcohols and vicinal diamines. The proposed reaction involves the formal insertion of group IV imidometal complexes (LxM=NR, M = Ti or Zr) across the C-X bond (X = O or NP) of epoxides and aziridines. Protonation of the resulting metallacycle is anticipated to liberate the desired vicinal amino-alcohol or diamine. The overall conversion of epoxide or aziridine to amino-alcohol or diamine should be possible in a single operation using catalytic imidometal complex when a stoichiometric amine is used as the proton source. When appropriate chiral, non-racemic ligands are employed, this sequence should be capable of asymmetric catalysis via the desymmetrization of meso substrates or the kinetic resolution of racemic substrates. Depending upon the results of the mechanistic investigations, the dynamic kinetic resolution of racemic substrates may be possible. Ultimately, this method is expected to allow rapid and stereocontrolled access to vicinal amino-alcohols and diamines.