Ultra fast method for chiral catalyst discovery
This invention is a novel method for determining--in less than 24 hours--enantiomeric ratios, percent conversions, and absolute configurations of all members of a chemical library containing at least 10,000 reaction products. Reaction mixtures are immobilized on a surface and then combined with fluorescent identification reagents that react at different rates with products of different chirality. Reaction products are analyzed simply by measuring their fluorescence.
Reaction microarrays allow researchers to identify products with high enantiomeric excess from libraries of thousands of reaction mixtures in hours rather than weeks. About 0.02 nmoles of product from each reaction is arrayed and immobilized on a 1x3-inch glass slide. A large excess of identification reagent can be used to drive the reaction to completion, and the chip can be easily rinsed clean. Because of the small amounts of product immobilized on the chip surface, 100 equivalents of identification reagent amounts to only about 0.3 mg for a 10,800-reaction slide, minimizing the costs of analysis. Since reaction microarrays are used to analyze reaction products, they are amenable to standard catalysis discovery methods that involve the variation of ligand structure, reaction conditions, and additives, as well as to combinatorial discovery methods. Furthermore, reaction microarrays employ the same instrumentation as DNA microarrays, and therefore benefit from the constant improvements made in robotic arraying, contact printing, and laser scanning.
Intellectual Property Status: Patent(s) Pending
While combinatorial chemistry has been successfully applied to the problem of chiral catalyst discovery, its utility is severely hampered by the lack of rapid, high-throughput screens for enantiomeric purity. Current methods require weeks to screen the products of 10,000 reactions. As a consequence, chemical companies face an increasing need for high throughput methods capable of efficiently producing enantiomerically pure products.
According to a study by the market research firm Frost and Platt, the worldwide market for chiral fine chemicals sold as single enantiomers is expected to grow at a rate of 13.2% annually; sales were up from $6.63 billion in 2000 to $16 billion in 2007.