A new chiral metalladiphosphine for early-late chemistry. Crystal structure of a D-camphor-based zirconium enolato phosphine and rearrangement of heterobimetallic Zr/Pd complexes

摘要

The bis(phosphinoenolato) zirconocene 2, prepared from the phosphino camphor derivative 3-exo-PPh2C10H150 1, represents the first C2-symmetric chiral diphosphine containing an early transition metal centre tethered to the phosphino groups via an enolato linkage. It allows the selective assembly of Lewis-acid early—late bimetallic combinations, as exemplified with the Zr/Cu and Zr/Ag complexes 4 and 5. The monophosphinoenolato titanocene 3 was also prepared. Reactions of 2 or 3 with [Pd(dmba)(p-CI)h (dmba o-C6H4CH2NMe2) or [PdCI4SEt2)2] led to complete transfer of the functional ligand to the Pd(ii) centre, with formation of f(dmba)Pd(PPh2C10H146)] 6 or cis-tPd(PPh2C10H146)21 8 and fCp2ZrCI2]/fCp2TiCI2J. respectively. A heterobimetallic Zr/Pd intermediate complex 10 of this rearrangement could be detected. Complexes 6 and 8 were prepared independently by reaction of I with [Pd(dmba)(p-CI)]2 or [Pd(SEt2)2Clj, respectively, which first afforded complexes 7 and 9 which were then treated with KH. The crystal structures of 2, 6 and 8THFH20 have been determined by X-ray diffraction.