Chiral Rhodium(III) Complex-Catalyzed Cascade Michael-Alkylation Reactions: Enantioselective Synthesis of Cyclopropanes

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• 作者：Gui-Jun Sun ; Jun Gong ; Qiang Kang
• 刊名：Journal of Organic Chemistry
• 出版年：2017
• 出版时间：January 6, 2017
• 年：2017
• 卷：82
• 期：1
• 页码：796-803
• 全文大小：486K
• ISSN：1520-6904

文摘

Chiral Rh(III) complex catalyzed highly efficient enantioselective cyclopropanation of α,β-unsaturated 2-acyl imidazoles or pyridine with 2-bromomalonate is developed to generate corresponding multisubstituted cyclopropanes in 70–99% yields with 93→99% enantioselectivity. The proficiency of the process is also demonstrated in gram scale reaction maintaining same reactivity and selectivity level in lower catalyst loading. Moreover, the developed methodology is applicable in challenging synthesis of biscyclopropane scaffold with 97% ee in a single operation.