Research Projects
Organic Synthesis Using Low Valent Complexes of Early Transition Metals
Within the last several years, the Livinghouse group has become heavily engaged in the development and application of synthetic methods involving low valent group IV and group V metals. The first synthetically practical zirconocene equivalent was discovered in our laboratory. This reagent, [(Cp)2Zr(DMAP)2], possesses sequentially displaceable dimethylaminopyridine ligands which permit its use in intermolecular two component coupling reactions involving unsymmetri-cal partners (Tetrahedron Lett.,30, 3495, 1989). Moreover, this species and related complexes have proven to be exceptionally versatile reagents for promoting enyne macrocyclization reactions (Tetrahedron,50, 4421, 1995) as well as the cocylization of hydrazone moieties with carbon-carbon multiple bonds (J. Am. Chem. Soc.,111, 4495, 1989). In addition, the Livinghouse group has reported the first synthetically practical examples of intramolecular [2+2] cycloadditions involving group IV metal-imido complexes and alkynes (J. Am. Chem. Soc.,114, 5459, 1992). The synthetic viability of this new methodolo-gy was subsequently demonstrated by us in a concise total synthesis of the indolizidine alkaloid (±)-monomorine (J. Org. Chem.,57, 1323, 1992) and the potent antifungal (+)-preussin (J. Am. Chem. Soc.,115, 11485, 1993). In addition, we have shown that a wide variety of functionally differentiated heterocycles can be synthesized using this methodology (Organometallics,16, 1523, 1997).
Personnel:
Thomas Livinghouse
Keywords:
Organic, Synthesis
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