Catalytic Asymmetric Cascade Using Spiro-Pyrrolidine Organocatalyst: Efficient Construction of Hydrophenanthridine
Jin-Miao Tian1, Yong-Hai Yuan2, Yu-Yang Xie1
1School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University , Shanghai 200240, China.
Abstract:
A newly developed SPD (spiro-pyrrolidine) organocatalyst has been demonstrated to enable an asymmetric aza-Michael/Michael/aldol cyclization cascade, in which two six-membered rings (B/C) and three stereocenters have been constructed in a catalytic one-step process. It is so far the most efficient method for construction of hydrophenanthridine derivatives featuring high enantioselectivity. The trans- or cis-fused B/C-rings can be selectively assembled in a substrate-controlled manner. Moreover, this cascade could magnify to gram scale without loss of enanioselectivity.
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