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A Novel Catalyst System for the Efficient Syntheses of Chiral Alcohols

技术优势

The chiralligand may be recycled. Provides highyields (>87%) and enantioselectivities (>90%) for a wide range ofsubstrates in various reactions  The catalystsystem uses inexpensive alkyl-zinc reagents.

详细技术说明

Georgetown University is seeking apartner interested in the commercial application of a novel ligand, catalystsystem. Chiral alcohols represent a fundamental component of many activepharmaceuticals and intermediates. The chiral bisoxazolidine ligand developedat Georgetown is very effective in mediating the syntheses of a variety ofchiral alcohols from aldehydes. Reactions performed with this system employ lowcost alkyl zincs, making this catalyst an atom economical and cost-effectivetool for synthesizing chiral alcohol products and intermediates.

*Abstract

*Publications

Liu S, Wolf C. Chiral Amplification based onenantioselective dual-phase distribution of a scalemic bisoxazolidinecatalyst. Org Lett. 2007 Aug 2;9(16):2965-8.Bisoxazolidine-catalyzed enantioselective alkynylation of aldehydes.  J Am Chem Soc. 2006 Aug 30;128(34):10996-7.INVENTORS  Christian Wolf and Shuanglong Liu

*Stage of Development

A readily synthesized C2-symmetricbisoxazolidine ligand was found to catalyze the asymmetric alkylation ofaldehydes with diethyl zinc (Et2Zn) and less reactive dimethyl zinc (Me2Zn), providinghigh yields and enantioselectivities. The bisoxazolidine ligand was alsosuccessfully applied in the catalytic enantioselective alkynylation of a rangeof aromatic and aliphatic aldehydes generating chiral propargylic alcohols inhigh yields and enantioselectivities. The same system effectively catalyzed theasymmetric Henry reaction of aliphatic and aromatic aldehydes to produce β-hydroxynitroalkanes in up to 99% yield and 95% ee. The nitroaldol formation requiresrelatively short reaction times in mild conditions and is applicable to a widerange of substrates including sterically hindered aldehydes.

国家/地区

美国