title: Insertion/Rearrangement Reactivity of a Lutetacyclopentadiene towards N,N'-Diphenylcarbodiimide: Cooperative Effect of the Metal Center, Concentration of LiCl, and Solvent.
abstract: The reactivity of lutetacyclopentadiene towards N,N'-diphenylcarbodiimide (DPC) was systematically investigated to efficiently construct three types of new N-containing fused cyclic complexes. The outcome of these reactions significantly depended on the the metal center, the concentration of LiCl, the number of equivalents of DPC, and the solvent. Thus, two unexpected reaction modes of amidinate were discovered for the first time, which were ascribed to an unusual κ(1) coordination mode of amidinate driven by a rigid seven-membered ring. These results are in striking contrast with the previously well-investigated zirconacyclopentadiene, which reacts with DPC to give azazirconacyclopentene and alkyne through β,β' CC bond cleavage. The difference in reactivity between lutetacyclopentadiene and zirconacyclopentadiene can be attributed to the highly ionic character of the LuC(sp(2) ) bonds. DFT calculations agreed well with the experimental results.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10-62751708.
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10-62751708.
authors.forename: Junnian
authors.initials: J
authors.lastname: Wei
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10-62751708. wx_zhang@pku.edu.cn.|State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071 (P.R. China). wx_zhang@pku.edu.cn.
authors.forename: Wen-Xiong
authors.initials: WX
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871 (P.R. China), Fax: (+86) 10-62751708.
authors.forename: Zhenfeng
authors.initials: Z
authors.lastname: Xi
keywords: N ligands; cooperative effects; lanthanides; metallacycles; rearrangement