CATALYTIC ENANTIOSELECIVE SYNTHESIS OF ALLYLAMINES

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While great advances have been made in asymmetric C-C bond formation utilizing chiral Lewis acids, less attention has been focused on the construction of C-N bonds with high levels of selectivity. This research proposal describes the development of a catalytic enantioselective method to synthesize allylamines via a [3,3] sigmatropic rearrangement. This study aims to extend the scope of enantioselective reactions catalyzed by bis(oxazoline)- metal Lewis acid complexes. The knowledge about these systems from structural and mechanistic studies of these Lewis acids by Evans provides a foundation on which to test this hypothesis. The proposal first presents acyl isocyanates as bidentate substrates that will allow the utilization of organized cationic bis(oxazoline)-copper-substrate complexes for asymmetric induction. Addition of substituted allylic ethers or thioethers to the Lewis acid activated acyl isocyanate generates a reactive intermediate bound to the chiral ligand-metal complex. The subsequent [3,3] rearrangement proceeds in a chiral environment, thus providing a chiral allylamine doubly protected as an acylcarbamate. Use of the bidentate bis(oxazoline) ligand provides chiral allylamines with the opposite stereochemistry at the newly formed center compared to the use of the tridentate pyridyl-bis(oxazoline) ligands of the same absolute configuration. The successful realization of the experiments described within will evaluate the ability of this bis(oxazoline)-metal complexes to catalyze asymmetric sigmatropic rearrangements. Information gained from these experiments will be utilized to develop new catalytic enantioselective reactions.