Byrne Joseph P, Delgado Lidia, Paradisi Francesca, Albrecht Martin
Departement für Chemie Biochemie und Pharmazie Universität Bern Freiestrasse 3 3012 Bern Switzerland.
School of Chemistry National University of Ireland Galway University Road Galway H91 TK33 Ireland.
ChemCatChem. 2022 Apr 7;14(7):e202200086. doi: 10.1002/cctc.202200086. Epub 2022 Mar 11.
Two sets of carbohydrate-NHC hybrid iridium complexes were synthesised in order to combine properties of carbohydrates and triazolylidene (trz) ligands in organometallic catalysis. One set features a direct trz linkage to the anomeric carbohydrate carbon, while the second set is comprised of an ethyl linker between the two functional units. Deprotection of the carbohydrate afforded hybrid complexes that efficiently catalyse the direct hydrogenation of ketones in water. The catalytic activity of the hybrid complexes was influenced by the pH of the aqueous medium and surpassed the activity of carbohydrate-free or acetyl-protected analogues (>90 % vs 13 % yield). While no enantiomeric induction was observed for the ethyl-linked hybrids, a moderate enantiomeric excess () was induced by the directly linked systems. Moreover, these carbohydrate-trz hybrid complexes displayed mixed inhibitory activity towards a glycosidase from that contain a glucose binding site.
合成了两组碳水化合物-NHC杂化铱配合物，以便在有机金属催化中结合碳水化合物和三唑亚基（trz）配体的性质。第一组的特点是trz直接连接到异头碳水化合物碳上，而第二组由两个功能单元之间的乙基连接基组成。碳水化合物的脱保护得到了能在水中有效催化酮直接氢化的杂化配合物。杂化配合物的催化活性受水介质pH值的影响，且超过了无碳水化合物或乙酰保护类似物的活性（产率分别为>90%和13%）。虽然未观察到乙基连接的杂化物有对映体诱导作用，但直接连接的体系诱导了适度的对映体过量（）。此外，这些碳水化合物-trz杂化配合物对含有葡萄糖结合位点的一种糖苷酶表现出混合抑制活性。
