Highly enantioselective γ-amination by N-heterocyclic carbene catalyzed [4+2] annulation of oxidized enals and azodicarboxylates.
γ-Amination: The title reaction was developed to give the corresponding dihydropyridazinones in good yields with excellent enantioselectivities (see scheme; Mes=2,4,6-trimethylphenyl). The annulation reaction worked well for γ-aryl, γ-alkyl, or γ-alkenyl oxidized enals. Highly enantiopure tetrahydropyridazinones and γ-amino acid derivatives could be easily prepared by chemical transformations of the resulting dihydropyridazinones.
Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (China).
Xiang-Yu
XY
Chen
Fei
F
Xia
Jin-Tang
JT
Cheng
Song
S
Ye
N-heterocyclic carbene; annulation; heterocycles; synthetic method; γ-amino acids