Highly efficient asymmetric synthesis of enantiopure dihydro-1,2-oxazines: dual-organocatalyst-promoted asymmetric cascade reaction.
A one-pot dual-organocatalyst-promoted asymmetric α-aminoxylation/aza-Michael/aldol consendation cascade reaction is presented. The targeted optically active 1,2-oxazine derivatives are synthesized in moderate yields (up to 70%), excellent enantioselectivities (ee >99% in all cases), and excellent diastereoselectivities (dr up to >99:1) under mild conditions. To further elucidate the synthetic utility of the cascade products, cleavage of the N-O bond is demonstrated and an enantiopure syn-1,4-amino alcohol derivative is achieved in excellent yield.
Department of Chemistry, Fudan University, 220 Handan Lu, Shanghai 200433, PR China.
Hua
H
Lin
Yu
Y
Tan
Xing-Wen
XW
Sun
Guo-Qiang
GQ
Lin
D000447:Aldehydes / Q000737:chemistry; D000605:Amino Alcohols / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D015394:Molecular Structure; D010078:Oxazines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D000605:Amino Alcohols; D010078:Oxazines; C116609:3-hydroxybutanal