Synthesis of Bridged Cyclopentane Derivatives by Catalytic Decarbonylative Cycloaddition of Cyclobutanones and Olefins
作者:Xuan Zhou、Haye Min Ko、Guangbin Dong
DOI:10.1002/anie.201608158
日期:2016.10.24
decarbonylative coupling between cyclobutanones and alkenes that proceeds by C−C activation and provides a distinct approach to a diverse range of saturated bridged cyclopentane derivatives. In this reaction, cyclobutanones serve as cyclopropane surrogates, reacting in a formal (4+2−1) transformation. To demonstrate the efficacy of this method, it was applied in a concise synthesis of the antifungal drug Tolciclate
Atom- and Step-Economical Pathway to Chiral Benzobicyclo[2.2.2]octenones through Carbon-Carbon Bond Cleavage
作者:Lantao Liu、Naoki Ishida、Masahiro Murakami
DOI:10.1002/anie.201108446
日期:2012.3.5
nickel‐catalyzed asymmetric intramolecular alkene insertion reaction into cyclobutanones (1) has been developed. The reaction significantly reduces the number of steps required for the synthesis of chiralbenzobicyclo[2.2.2]octenones (2).
Nickel-catalysed intramolecular alkene insertion into cyclobutanones
作者:Masahiro Murakami、Shinji Ashida
DOI:10.1039/b611522e
日期:——
A nickel(0) catalyst converted 3-styrylcyclobutanones into benzobicyclo[2.2.2]octenones by an intramolecular insertion of the vinyl moiety into the cyclobutanone skeleton.
Cooperative activation of cyclobutanones and olefins leads to bridged ring systems by a catalytic [4 + 2] coupling
作者:Haye Min Ko、Guangbin Dong
DOI:10.1038/nchem.1989
日期:2014.8
Bridged ring systems are widely found in natural products, and successful syntheses of them frequently feature intramolecular DielsâAlder reactions. These reactions are subclassified as either type I or type II depending on how the diene motif is tethered to the rest of the substrate (type I are tethered at the 1-position of the diene and type II at the 2-position). Although the type I reaction has been used with great success, the molecular scaffolds accessible by the type II reactions are limited by the strain inherent in the formation of an sp2 carbon at a bridgehead position. Here, we describe a complementary approach that provides access to these structures through the CâC activation of cyclobutanones and their coupling with olefins. Various alkenes have been coupled with cyclobutanones to provide a range of bridged skeletons. The ketone group of the products serves as a convenient handle for downstream functionalization. Although widely used to form bridged ring systems, certain intramolecular DielsâAlder reactions are hampered by the strain inherent in forming an sp2-carbon at a bridgehead position. Now, an alternative strategy has been described to access these bridged ring systems through the CâC activation and coupling of cyclobutanones with olefins.
桥环系统广泛存在于天然产物中,成功合成桥环系统的方法通常是分子内 DielsâAlder 反应。根据二烯基团与底物其他部分的连接方式,这些反应又可分为 I 型和 II 型(I 型是在二烯的 1 位连接,II 型是在 2 位连接)。虽然 I 型反应取得了巨大成功,但 II 型反应所能获得的分子支架受到了桥头位置形成 sp2 碳所固有的应变的限制。在这里,我们将介绍一种补充方法,通过环丁酮的 CâC 活化及其与烯烃的偶联来获得这些结构。各种烯烃与环丁酮的偶联提供了一系列桥接骨架。产物中的酮基可以方便地进行下游官能化。虽然桥环体系被广泛应用于形成桥环体系,但某些分子内 DielsâAlder 反应会受到在桥头位置形成 sp2 碳所固有的应变的影响。现在,一种通过环丁酮与烯烃的 CâC 活化和偶联来获得这些桥环体系的替代策略已经问世。
Catalyzed Intramolecular Olefin Insertion into a Carbon−Carbon Single Bond
作者:Masahiro Murakami、Tamon Itahashi、Yoshihiko Ito
DOI:10.1021/ja021062n
日期:2002.11.1
treatment of cyclobutanone bearing an o-styryl group at the 3-position with a catalytic amount of a cationic rhodium(I)-dppp complex. Initially, rhodium is inserted between the carbonyl carbon and the alpha-carbon of the cyclobutanone. Intramolecular coordination of the vinyl group results in its migratory insertion into the C-Rh linkage. Reductiveelimination affords benzobicyclo[3.2.1]octan-3-one. Notably