Insertion/Rearrangement Reactivity of a Lutetacyclopentadiene towards N,N-Diphenylcarbodiimide: Cooperative Effect of the Metal Center, Concentration of LiCl, and Solvent

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 (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 , CC bond cleavage. The difference in reactivity between lutetacyclopentadiene and zirconacyclopentadiene can be attributed to the highly ionic character of the LuC(sp(2)) bonds. DFT calculations agreed well with the experimental results.Natural Science Foundation of China; "973" program from MOST of China [2012CB821600]SCI(E)EIPubMedARTICLEwx_zhang@pku.edu.cn4415860-158662