Highly enantioselective oxazaborolidine-catalyzed reduction of 1,3-dicarbonyl compounds: role of the additive diethylaniline.
The oxazaborolidine-catalyzed reduction of 2,2-disubstituted cycloalkan-1,3-diones or hindered 2,2-disubstituted cyclic ketones using catecholborane as reductant proceeds with greater enantioselectivity when N,N-diethylaniline is added. It has now been shown that the effect of this additive is to catalyze the conversion of a harmful minor impurity in catalyst preparations to the active catalyst.
Chein
Rong-Jie
RJ
Department of Chemistry and Chemical Biology, Harvard University Cambridge, Massachusetts 02138, USA.
Yeung
Ying-Yeung
YY
Corey
E J
EJ