Enantioselective Synthesis of Polysubstituted Benzopyrano[3,4-c]pyrrolidine Frameworks via [3 + 2] Cycloaddition of Azomethine Ylides and Coumarin Derivatives.
An enantioselective synthesis of benzopyrano[3,4-c]pyrrolidine derivatives via organocatalyzed [3 + 2] cycloaddition has been achieved. Cinchona alkaloid-derived organocatalysts as Brønsted bases have been examined for this asymmetric cycloaddition of o-hydroxy aromatic aldimines with 3-substituted coumarins. An unexpected rearrangement of the quaternary acyl moiety in the products resulted in an in situ protection of the o-hydroxy group.
Department of Chemistry, National Taiwan Normal University , Taipei 11677, Taiwan, R.O.C.
Geng-Hua
GH
Chang
Department of Chemistry, National Taiwan Normal University , Taipei 11677, Taiwan, R.O.C.
Chein-Yi
CY
Wang
Department of Chemistry, National Taiwan Normal University , Taipei 11677, Taiwan, R.O.C.
G
G
Madhusudhan Reddy
Department of Chemistry, National Taiwan Normal University , Taipei 11677, Taiwan, R.O.C.
Yi-Ling
YL
Tsai
Department of Chemistry, National Taiwan Normal University , Taipei 11677, Taiwan, R.O.C.
Wenwei
W
Lin