ABSTRACT
A highly efficient chiral gold phosphate-catalyzed tandem hydroamination/asymmetric transfer hydrogenation reaction is described. A series of chiral tetrahydroquinolines were obtained in excellent yields and enantioselectivities. In this reaction, the gold catalyst enables both the hydroamination step as a π-Lewis acid and the asymmetric hydrogen-transfer process as an effective chiral Lewis acid.
Subject(s)
Gold/chemistry , Phosphates/chemistry , Quinolines/chemical synthesis , Amination , Catalysis , Hydrogenation , Molecular Structure , Quinolines/chemistry , StereoisomerismABSTRACT
A little gold goes a long way: as little as 0.01 mol % of chiral gold phosphate is sufficient to afford the asymmetric transfer hydrogenation of quinolines with high stereoselectivity (up to 98 % ee). The achiral ligands on gold were found to have considerable effect on the catalytic efficiency.
Subject(s)
Gold/chemistry , Hydrogen/chemistry , Quinolines/chemistry , Anions/chemistry , Catalysis , Hydrogenation , Ligands , Molecular Structure , Phosphates/chemistry , Stereoisomerism , Substrate SpecificityABSTRACT
A chiral phosphoric acid-catalyzed intramolecular 1,3-dipolar cycloaddition of 4-(2-formylphenoxy)butenoates with amino esters provides hexahydromeno[4,3-b]pyrrolidine derivatives in high enantioselectivity (up to 94% ee).