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Dear Friends of Fluorous,
We always appreciate the interest that all of you reading this newsletter have in our technology, but there are still many of you out there that we’d like to call a friend AND a customer. “April showers bring forth May flowers” chants the old rhyme, so it’s time for us to shower our fluorous-curious friends with a little affection (in the form of a new customer promotion described below) that will hopefully blossom into a deeper relationship. I hope you enjoy the rest of our latest installment of fluorous news and information as well; the team at FTI certainly enjoys bringing it to your attention.
Cheers,
Phil
Philip E. Yeske
President & CEO
Product Promotion for New Customers
Have you heard? Fluorous can help you in a variety of ways to do your job more efficiently! Curious, but unconvinced? Well here's your chance to take advantage of a great sales promotion being offered to any first-time customer: place an order anytime during the month of May and a 20% discount will be applied to any purchase order of fluorous reagents; Just ask for the May New Customer Discount. Remember - this offer is good on the purchase of any of the fluorous reagents offered on our website catalog. Do it today!
Fluorous Lawesson's Reagent
A widely applied procedure used in the synthesis of organosulfur compounds is thionation: the conversion of a carbonyl group to a thiocarbonyl. Lawesson’s reagent (LR) is often used in this reaction for its broad utility and efficiency however a commonly reported shortcoming is the lack of a method to remove the LR-derived byproducts. A fluorous version of LR was developed by Soós et al (Soós, T., et al, Organic Letters 2006, 8, 1093-1095) with the expectation that the fluorous tag would simplify product isolation using a fluorous solid phase extraction (F-SPE) rather than chromatographic isolation.
Several experiments were carried out using amides, esters and ketones. A series of experiments involving the conversion of benzamide to thiobenzamide were first conducted using a fluorous LR having an Rf8 tag and then compared to a fluorous LR having an Rf6 tag (Dembinski, R., et al, Organic Letters 2006, 8, 1625-1628). The reactions proceeded efficiently with high yields obtained using either fluorous LR in conjunction with F-SPE. The Rf6-LR was further evaluated in the synthesis of five-membered ring heterocycles since these are an important class of compounds that were easily converted into 2,5-substituted thiophenes. In all cases, the purity of these sulfur-containing compounds was confirmed by 1H and 13C NMR after F-SPE, with no fluorous LR or its byproducts being observed. By combining fluorous LR with microwave chemistry, rapid synthesis and isolation of target compounds in high purity and yield was achieved. If you are interested in a fluorous Lawesson’s Reagent for your research, send us an email.
Fluorous Continues to Evolve
Fluorous tags have been used successfully in medicinal and combinatorial chemistry for several years, and FTI has a wide range of products available to serve this market. More recently, the utility of these tags has been demonstrated in biomolecular fields such as oligonucleotide synthesis (Bannwarth, W., et al, Helv. Chim. Acta. 2005, 88, 171-179), oligosaccharide synthesis (Pohl, N. L., et al, J. Am. Chem. Soc. 2005, 127, 13162-13163) and peptide synthesis (van Boom, J. H., et al, Tetrahedron Lett. 2002, 43, 7809-7812) as well as proteomics (Peters, E. C., et al, Nat. Biotech. 2005, 23, 463-469). In 2005 Berry & Associates, Inc., under license from FTI, launched a series of fluorous products for the oligonucleotide synthesis market. Berry recently announced the receipt of an SBIR Phase II research grant from the National Institutes of Health to continue their research in the development of fluorous methods for the purification of oligonucleotides in applications such as genetics, diagnostics and therapeutics. In Phase I work, a method was developed using fluorous affinity purification, in which the oligonucleotide is fluorous tagged allowing for easy capture of the desired component during a purification step while non-fluorous impurities and deletion sequences are eluted from the cartridge (Pearson, W.H., et al, J. Org. Chem. 2005, 70, 7114-7122). On-cartridge detagging and further elution provides the desired oligonucleotide. Ease of use, improved yields, selectivity and purity were all noted using fluorous techniques. Congratulations to our friends at Berry and Associates and we look forward to more great developments!
Think you have an interesting idea or market application for fluorous technology that could benefit from a similar collaborative relationship with FTI? Let us know - we would welcome the opportunity to discuss it with you.
Top 10 Most-Accessed Articles
In another indication of the high level of interest in fluorous chemistry, “Plate-to-Plate Fluorous Solid-Phase Extraction for Solution-Phase Parallel Synthesis” was one of the top 10 most frequently accessed articles in the Journal of Combinatorial Chemistry in the 4th quarter of 2005. This article (Zhang, W. et al, J. Comb. Chem. 2005, 7, 893) described the use of a 24-well filter plate loaded with FluoroFlash® silica gel for parallel F-SPE. Three reactions types were demonstrated using the 24-well plate including a fluorous scavenging reaction and two different fluorous coupling reagents.
FTI scientists continue to develop new techniques designed to increase your productivity. Currently we are working on 96-well F-SPE plates using a new gravity based, water-free F-SPE protocol. The 96-well plate is in beta-testing, so if you are interested in increasing your productivity using these plates, please contact us.
ACS "TAOC" Award
Just Announced – Congratulations to FTI's own Yimin Lu, who was recently selected as one of the winners of the 2006 Technical Achievements in Organic Chemistry Award (TAOC) by the Division of Organic Chemistry of the American Chemical Society. While working at FTI Yimin has made significant contributions to the development of fluorous synthesis and separation techniques as applied to parallel and combinatorial synthesis. Yimin will receive his award at the 232nd ACS meeting in San Francisco this September.