0000000000976796
AUTHOR
István Szatmári
Microwave-assisted, highly enantioselective addition of diethylzinc to aromatic aldehydes catalyzed by chiral aminonaphthols
Abstract New optically active aminonaphthols were obtained by condensation of 2-naphthol, benzaldehyde and ( R )-(+)-1-(1-naphthyl)ethylamine or ( R )-(+)-1-(2-naphthyl)ethylamine. Their N-methylated derivatives were also synthesized. The new aminonaphthols 2 , 4 , 5 and 7 were found to catalyze the enantioselective ethylation of aryl aldehydes to 1-aryl-1-propanols (up to 92% ee). The reactions were accelerated greatly by microwave irradiation.
Synthesis and stereochemical studies of 1- and 2-phenyl-substituted 1,3-oxazino[4,3-a]isoquinoline derivatives
Abstract Starting from the 1′- or 2′-phenyl-substituted 1-(2′-hydroxyethyl)-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline diastereomers 3 and 6 , 4-unsubstituted and 4-(p-nitrophenyl)- and 4-oxo-substituted 1-phenyl- and 2-phenyl-9,10-dimethoxy-2H,4H-1,6,7,11b-tetrahydro-1,3-oxazino[4,3-a]isoquinolines ( 7–12 ) were prepared. The relative configurations and the predominant conformations of the products were determined by NMR spectroscopy, by quantum chemical calculations and, for (2R∗,4S∗,11bR∗)-9,10-dimethoxy-4-(p-nitrophenyl)-2-phenyl-2H,4H-1,6,7,11b-tetrahydro-1,3-oxazino[4,3-a]isoquinoline ( 11 ), by X-ray diffraction.