Enantioselective Synthesis of Functionalized Polycarbocycles via a Three-Component Organocascade Quadruple Reaction

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• 作者：Yun-Pu Chang ; Ramani Gurubrahamam ; Kwunmin Chen
• 刊名：Organic Letters
• 出版年：2015
• 出版时间：June 19, 2015
• 年：2015
• 卷：17
• 期：12
• 页码：2908-2911
• 全文大小：347K
• ISSN：1523-7052

文摘

An efficient organocascade quadruple reaction was conducted to synthesize a functionalized spiropolycyclic scaffold in high chemical yields (43鈥?0%) and excellent levels of stereoselectivity (up to >19:1 dr and 99% ee). The quadruple reaction proceeded smoothly between 1,3-indanedione and aromatic aldehydes with concomitant desymmetrization of prochiral 4-substituted cyclohexanones through the Knoevenagel/Michael/aldol/aldol reaction sequence catalyzed by a bifunctional thiourea catalyst. Two of the formed products were transformed into spirocyclic epoxides containing four contiguous quaternary centers.