Enantioselective direct aza hetero-Diels-Alder reaction catalyzed by chiral Brønsted acids.

Hua Liu, Lin-Feng Cun, Ai-Qiao Mi, Yao-Zhong Jiang, Liu-Zhu Gong

Index: Org. Lett. 8 , 6023, (2006)

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Abstract

[Structure: see text] The first chiral Brønsted acid-catalyzed asymmetric direct aza hetero-Diels-Alder reaction has been described. The phosphoric acids, prepared from binol and H8-binol derivatives, have shown catalytic ability for the reaction of cyclohexenone with N-PMP-benzaldimine. A chiral phosphoric acid, derived from 3,3-di(4-chloropheneyl)-H8-binol, exhibited superior enantioselectivity, affording fairly good yields and enantioselectivities for the reaction of a range of aromatic aldimines with cyclohexenone.