Substrate Range of the Titanium TADDOLate Catalyzed Asymmetric Fluorination of Activated Carbonyl Compounds
作者:Andreas Bertogg、Lukas Hintermann、Dominique P. Huber、Mauro Perseghini、Maria Sanna、Antonio Togni
DOI:10.1002/hlca.201100375
日期:2012.3
4‐diazoniabicyclo[2.2.2]octane bis‐[tetrafluoroborate]) at room temperature. A series of α‐methylated β‐keto esters (3‐oxobutanoates, 3‐oxopentanoates) with bulky benzyl ester groups (60–90% ee) or phenyl ester (67–88% ee) have been fluorinated readily, whereas α‐acyl lactones were also readily fluorinated, but gave lower inductions (13–46% ee). Double stereochemical differentiation in β‐keto esters with chiral
TiIV-Catalyzed Asymmetric Sulfenylation of 1,3-Dicarbonyl Compounds
作者:Marjan Jereb、Antonio Togni
DOI:10.1002/chem.200700920
日期:2007.11.16
The electrophilic enantioselective sulfenylation of 1,3-dicarbonylcompounds with phenylsulfenyl chloride is effectively catalyzed by [Ti(TADDOLato)] complexes. The corresponding products are obtained in moderate to high yields. The highest ee values (up to 97 %) are obtained in toluene at room temperature and with a typical catalyst loading of 5 mol %. Bulky ester groups and sterically undemanding