Feng Yi-Jhen, Chen Yi-Hsin, Huang Shou-Ling, Liu Yi-Hung, Lin Ying-Chih
Department of Chemistry, National Taiwan University, Taipei, 106, Taiwan), Fax: (+886) 223636359.
Chem Asian J. 2017 Dec 5;12(23):3027-3038. doi: 10.1002/asia.201701070. Epub 2017 Nov 9.
Reactions of the ruthenium complex [Ru]Cl ([Ru]=Cp(PPh ) Ru; Cp=η -C H ) with several aryl propargyl acetates, each with an ortho-substituted chain of various length containing an epoxide on the aromatic ring and with or without methyl substitutents on the epoxide ring, bring about novel cyclizations. The cyclization reactions of HC≡CCH(OAc)(C H )CH (RC H O) (R=H, 6 a; R=CH , 6 b, where RC H O is an epoxide ring) in MeOH give the vinylidene complexes 5 a-b, respectively, each with the Cβ integrated into a tetrahydro-5H-benzo[7]annulen-6-ol ring. A C-C bond formation takes place between the propargyl acetate and the less substituted carbon of the epoxide ring. Further cyclizations of 5 a-b induced by HBF give the corresponding vinylidene complexes 8 a-b each with a new 8-oxabicyclo-[3.2.1]octane ring by removal of a methanol molecule in high yield. For similar aryl propargyl acetates with a shorter epoxide chain, the cyclization gives a mixture of a vinylidene complex with a tetrahydronaphthalen-1-ol ring and a carbene complex with a tricyclic indeno-furan ring. For the cyclization of 18, with a longer epoxide chain, opening of the epoxide is required to afford the vicinal bromohydrin 22, then tandem cyclization occurs in one pot. Products are characterized by spectroscopic methods as well as by XRD analysis.
钌配合物[Ru]Cl（[Ru]=Cp(PPh ) Ru；Cp=η -C H ）与几种芳基炔丙基乙酸酯发生反应，这些芳基炔丙基乙酸酯各自具有不同长度的邻位取代链，该链在芳环上含有一个环氧化物，且环氧化物环上有或没有甲基取代基，反应会产生新颖的环化反应。HC≡CCH(OAc)(C H )CH (RC H O)（R=H，6 a；R=CH ，6 b，其中RC H O为环氧化物环）在甲醇中的环化反应分别生成亚乙烯基配合物5 a - b，每个配合物的Cβ都整合到一个四氢-5H-苯并[7]环壬烯-6-醇环中。在炔丙基乙酸酯和环氧化物环中取代较少的碳原子之间形成了一个C - C键。由HBF引发的5 a - b的进一步环化反应通过高产率地除去一个甲醇分子，得到相应的各自带有一个新的8-氧杂双环-[3.2.1]辛烷环的亚乙烯基配合物8 a - b。对于具有较短环氧化物链的类似芳基炔丙基乙酸酯，环化反应得到一种带有四氢萘-1-醇环的亚乙烯基配合物和一种带有三环茚并呋喃环的卡宾配合物的混合物。对于具有较长环氧化物链的18的环化反应，需要打开环氧化物以得到邻位溴代醇22，然后在一锅反应中发生串联环化。产物通过光谱方法以及XRD分析进行表征。
