Chemistry of the five-membered zirconacycloallenoids: reactions with unsaturated substrates
Chemistry of the five-membered zirconacycloallenoids: reactions with unsaturated substrates
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DOI：
10.1039/c2sc20745a
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发表时间：
2012-10
期刊：
影响因子：
8.4
通讯作者：
Georg Bender;G. Kehr;R. Fröhlich;J. L. Petersen;G. Erker
中科院分区：
文献类型：
--
作者：
Georg Bender;G. Kehr;R. Fröhlich;J. L. Petersen;G. Erker
二氯化锆与两个摩尔当量的二氯化锆处理后原位生成的二茂锆盐。在正丁基氯化镁的作用下，被烯炔类化合物R-CC-C(Me)CH2(R=-SiMe3，7c；R=叔丁基，7b)捕获，分别得到6b和6c的锆环烯类化合物。化合物6c添加额外的烯炔7c的等价物以形成七元炔插入产物9，其本身呈现典型的锆环烯结构。乙腈插入6c的Zr-C键还会形成一个七元金属环烯类化合物，分离为各自的烯胺基互变异构体10。化合物6c与两个摩尔当量的化合物反应。苯甲醛生成九元环烯丙烯。化合物6b加1摩尔当量。以产生在环结构内包含两个金属键合的联烯基团的九元金属环14。
Zirconocene, in situ generated by treatment of zirconocene dichloride with two molar equiv. of n-butyl magnesium chloride, is trapped by the enynes R–CC–C(Me)CH2 (R = –SiMe3, 7c; R = tert-butyl, 7b) to give the zirconacycloallenoids 6b and 6c, respectively. Compound 6c adds an additional equivalent of the enyne 7c to form the seven-membered alkyne insertion product 9 which itself exhibits a typical zirconacycloallenoid structure. Acetonitrile insertion into the Zr–C bond of 6c also results in the formation of a seven-membered metallacycloallenoid, isolated as the respective enamido tautomer 10. Compound 6c reacts with two molar equiv. of benzaldehyde to give a nine-membered cyclic allene. Compound 6b adds one molar equiv. of the enyne 7c to yield the nine-membered metallacycle 14 that contains two metal bonded allenoid moieties inside the ring structure.