From CO2 to Methanol by Hybrid QM/MM Embedding

✍ Scribed by Samuel A. French; Alexey A. Sokol; Stefan T. Bromley; C. Richard A. Catlow; Stephen C. Rogers; Frank King; Paul Sherwood

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 242 KB
• Volume: 40
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/1521-3773(20011203)40:23<4437::aid-anie4437>3.0.co;2-l

✦ Synopsis

General Procedure for the automated synthesis of oligosaccharides incorporating cap-tags: Octenediol-functionalized resin 12 was loaded into a reaction vessel equipped with a cooling jacket and inserted into a modified ABI-433A peptide synthesizer. The resin was glycosylated with donor 13 or 15 (5 equiv) in CH 2 Cl 2 (3 mL) with TMSOTf as activator. The suspension was mixed (10 s vortex, 50 s rest) for 15 min. The resin was then washed with CH 2 Cl 2 (6 Â 4 mL), and the unglycosylated sites were capped with A-Tag anhydride 2 or F-Tag triflate 11. The resin was subjected to the appropriate deprotection conditions followed by the washing cycle. The deprotected polymer-bound monosaccharide was then elongated by reiteration of the above glycosylation/capping/deprotection protocol. The final trisaccharide was not deprotected, so that analysis of the products was simplified. For A-Tag, the crude material was treated with tributylphosphine and water, liberated from the resin, then purified with an isocyanate scavenger resin. For F-Tag, the crude material was liberated from the resin and purified with fluorous silica gel.