Heteroallenes metal complexes

Heptane-4,6-dione, decafluoro-metal complexes decomposition, 385 Heptane-2,4,6-trione metal complexes, 399 Heteroallenes coordinated reactivity, 579 metal complexes, 579 Heterocyclic nitrogen compounds basic pKa... 

One other study of group 14 heteroallenes involving transition metals was reported in 1995. Jones et al. described the isolation of a ruthenium complex of a 1-silaallene (132—Scheme 32). The 1-silaallene also interacts with a hydrogen atom as well as the ruthenium metal center. Jones et al. describe this view... 

Analogous heterobimetallic tripodal amido complexes 1275 (M = Fe, Ru) undergo highly selective reactions with heteroallenes X=C=Y (C02, CS2, OGNPh, SCNMe, SCNPh) to yield the insertion products 1276 (Equation (65)).962 Single crystal X-ray structures of the products (1276 M = Fe X = Y = S X = S, Y = NPh) established the mode of coordination of the substrates to the two metal centers as depicted in Equation (65). The Zr-Fe complex CpFe(CO)2Zr(OBut)Cp2 reacts with 1 equiv. of CS2 to form the analogous stable dithiocarboxylate complex.963... 

Similar reactions can be performed starting from various heteroallenes (CO2, CS2, RN=C=NR, RN=C=S, RN=C=0) giving stable monomeric five-coordinated anionic complexes. Addition of diazoalkane to phosphanozir-conocenes leads to stable N-metal phosphazines (equation 19). 

C3-symmetrical tripodal ligands have been used to obtain amido complexes of family (86). If chiral substituents are present in the ligand periphery, some stereo discrimination is observed in the reaction with several chiral ketones and aldehydes. On the other hand, such systems can generate early-late heterobimetallics with metal-metal bonds (equation 41). Reaction of (91) with MeNC as well as the heteroallenes CO2, CS2, RNCO and RNCS led to insertion into the polar metal-metal bond. Tris (pyrazolyl) borate see Tris(pyrazolyI)borates) Zr and Hf complexes are other interesting examples of the type (86). In combination with MAO, they give promising results in ethylene and ethylene/hexene polymerizations. Substitution of these sterically crowded ligands allows adjustements of the environment of the active site to the... 

Scheme 4.8 Insertion of isonitriles and heteroallenes into the unsupported metal-metal bond of Zr-M heterodinuclear complexes.

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