Enantioselective arylation of 2-methylacetoacetates catalyzed by CuI/trans-4-hydroxy-L-proline at low reaction temperatures.
CuI/trans-4-hydroxy-l-proline-catalyzed coupling reaction of 2-iodotrifluoroacetanilides with 2-methylacetoacetates took place at -45 degrees C to create alpha-aryl all-carbon quaternary centers enantioselectively. Up to 93% ee was achieved when tert-butyl ester was used. The combination of ligand, ortho substituent (participation of NHCOCF3), and solvent effects was shown to account for these unprecedentedly mild reaction conditions.
Xie
Xiaoan
X
Department of Chemistry, Fudan University, Shanghai 200433, China.
Chen
Yu
Y
Ma
Dawei
D
D000090:Acetoacetates / Q000737:chemistry*; D002384:Catalysis; D003300:Copper / Q000737:chemistry*; D006909:Hydroxyproline / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D007454:Iodides / Q000737:chemistry*; D015394:Molecular Structure; D000078183:Oxindoles; D013237:Stereoisomerism; D013696:Temperature
D000090:Acetoacetates; D007211:Indoles; D007454:Iodides; D000078183:Oxindoles; C022960:2-oxindole; C037765:2-methylacetoacetic acid; D003300:Copper; C073870:cuprous iodide; D006909:Hydroxyproline