Mini-ISES identifies promising carbafructopyranose-based salens for asymmetric catalysis: Tuning ligand shape via the anomeric effect

• DOI: 10.1126/sciadv.1500066
• Publication Date: 2015-07-11T02:54:52Z
• Authors: Kannan R. Karukur...; Xiang Fei; Robert A. Swyka; Sylvain Broussy; Weijun Shen; Sangeeta Dey; Sandip K. Roy; David B. Berkowitz
• Keywords: Chemistry; 500; 540; 01 natural sciences; Research Articles; 0104 chemical sciences

This study introduces new methods of screening for and tuning chiral space in so doing identifies a promising set ligands asymmetric synthesis. The carbafructopyranosyl-1,2-diamine(s) salens constructed therefrom are particularly compelling. It is shown that by removing the native anomeric effect this ligand family, one can tune shape improve bias. concept demonstrated combination (i) x-ray crystallographic structure determination, (ii) assessment catalytic performance, (iii) consideration its underlying dipolar basis. title were identified mini version situ enzymatic (ISES) procedure through which catalyst-ligand combinations screened parallel, information on relative rate enantioselectivity obtained real time, without need to quench reactions or draw aliquots. Mini-ISES brings technique into nanomole regime (200 350 nmol catalyst/20 μml organic volume) commensurate with emerging trends reaction development/process chemistry. best-performing β-d-carbafructopyranosyl-1,2-diamine-derived salen discovered here outperforms best known organometallic catalysts hydrolytic kinetic resolution 3-phenylpropylene oxide, several substrates examined "matched." scaffold defines swath space, tunability shaping space. Both shape-tuning expected find broad application, given value 1,2-diamines from these catalysis.