Risgaard Tine, Gothelf Kurt V, Jørgensen Karl Anker
Danish National Research Foundation: Center for Catalysis, Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark.
Org Biomol Chem. 2003 Jan 7;1(1):153-6. doi: 10.1039/b208859m.
A catalytic enantioselective Henry reaction of silyl nitronates with aldehydes has been developed. Different chiral Lewis acids have been tested for the reaction and it has been found that a variety of chiral copper-ligand complexes can catalyze the Henry reaction. The best yield, diastereo- and enantioselectivity of the nitroalcohols formed are obtained by the application of a copper(II)-diphenyl-bisoxazoline complex as the catalyst in the presence of tetrabutylammonium triphenylsilyldifluorosilicate (TBAT). In order to minimize the epimerization of the nitroaldol products they were converted into the corresponding Mosher esters. The reaction proceeds well for different aromatic aldehydes reacting with alkyl nitronates.
已开发出一种甲硅烷基硝酸酯与醛的催化对映选择性亨利反应。已针对该反应测试了不同的手性路易斯酸，并且发现多种手性铜 - 配体配合物可催化亨利反应。在四丁基铵三苯基甲硅烷基二氟硅酸盐（TBAT）存在下，以铜（II）-二苯基 - 双恶唑啉配合物作为催化剂，可获得所形成的硝基醇的最佳产率、非对映选择性和对映选择性。为了使硝基醛醇产物的差向异构化最小化，将它们转化为相应的莫舍尔酯。该反应对于不同的芳族醛与烷基硝酸酯的反应进行得很好。
