Saturated and aromatic aldehydes react with Me2(C(CN)NR2 to give the corresponding R′CH(CN)NR2. Saturated aldehydes do not react with Me2C(CN)NHR but aromatic aldehydes yield Schiff bases (ArCHNR). α,β-Unsaturated aldehydes react with Me2C(CN)NR2 or Me2C(CN)NMR to form RCH2CHC(CN)NR2 (in both possible geometric forms) or RCH2CH2C(CN)NR.
A novel cationic [IrH(THF)(P,N)(imine)] [BArF] catalyst containing a P-stereogenic MaxPHOX ligand is described for the direct asymmetrichydrogenation of N-methyl and N-alkyl imines. This is the first catalytic system to attain high enantioselectivity (up to 94% ee) in this type of transformation. The labile tetrahydrofuran ligand allows for effective activation and reactivity, even at low temperatures
<scp>l</scp>-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines
作者:Chao Wang、Xinjun Wu、Li Zhou、Jian Sun
DOI:10.1039/c4ob01257g
日期:——
L-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst 3c afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.