Reductive aldol cyclizations of unsaturated thioester derivatives of 1,3-cyclopentanedione catalyzed by chiral copper hydrides

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• 作者：Jun Ou ; Wing-Tak Wong ; Pauline Chiu ; ^pchiu@hku.hk
• 关键词：Aldol reaction ; Reduction ; Cyclization ; Copper ; Enantioselective catalysis
• 刊名：Tetrahedron
• 出版年：2012
• 期刊代码：107_00404020
• 类别：ch
• 出版时间：29 April, 2012
• 卷：68
• 期：17
• 页码：3450-3456
• 文件大小：711 K

摘要

The first study on the asymmetric reductive aldol reactions of enethioate derivatives of 1,3-cyclopentanedione showed that 5聽mol聽%of TANIAPHOS (SL-T001-1), and Cu(OAc)₂路H₂O, together with phenylsilane as the stoichiometric reductant, generated the best yields and enantioselectivities of 尾-hydroxythioester products. With S-benzyl keto-enethioate as substrate, the bicyclo[4.3.0] hydroxythioester product was obtained only as the all-cis diastereomer, in good yield (84%) and enantioselectivity (up to 90%ee). With the related indanedione enethioate derivatives, the reductive aldol cyclization could attain up to 96%ee. These results demonstrate that enethioates have a significantly different reactivity and selectivity profile compared to enoate derivatives in the copper-catalyzed reductive aldol cyclization.