Synthesis of Optically Enriched Spirocyclic Benzofuran‐2‐ones by Bifunctional Thiourea‐Base Catalyzed Double‐Michael Addition of Benzofuran‐2‐ones to Dienones |
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Authors: | Prof. Xin Li Chen Yang Jia‐Lu Jin Xiao‐Song Xue Prof. Jin‐Pei Cheng |
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Affiliation: | Department of Chemistry, State Key Laboratory of Elemento‐Organic Chemistry, Nankai University, Tianjin 30071 (China) |
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Abstract: | A highly enantioselective catalytic double‐Michael addition reaction of substituted benzofuran‐2‐ones with divinyl ketones promoted by readily accessible tertiary amine–thiourea Cinchona alkaloids has been developed. A number of optically enriched spirocyclic benzofuran‐2‐ones were prepared in very good yields (up to 99 %), diastereoselectivities (up to 19:1 d.r.), and very good enantioselectivities (up to 92 % ee). Density functional theory (DFT) calculations were performed to investigate the origin of stereoselectivity. |
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Keywords: | asymmetric catalysis density functional calculations Michael addition organocatalysis spirocyclic benzofuran‐2‐ones |
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