Imido complexes synthesis

Lu E, Li Y, Chen Y. A scandium terminal imido complex synthesis, structure and DFT studies. Chem Commun. 2010 46 4469-4471. 

The Cp Ti(amidinate) fragment provides a particularly useful platform for the synthesis of novel titanium imido complexes and the study of their unusual reactivity. Numerous single-, double-, and cross-coupling and imido-transfer reactions were investigated using these compounds. The synthetic routes leading to CpTi and Cp Ti amidinate derivatives are outlined in Scheme... 

Other iron-imido complexes have also been reported. Holland and coworkers reported the synthesis of the imidoiron(III) complex [L FeNAd] [40, 41]. This imidoiron(III) complex has not been isolated and was found to convert to a purple high-spin iron(III) complex. It has an S = 3/2 ground state from EPR measurement. Based on the results of QM/MM computations, [L EeNAd] is a three-coordinated complex with an Fe-N distance of 1.68 A and has a nearly linear Fe=N-C unit with Fe-N-C angle of 174.1°. Chirik and coworkers made use of liable ligands to prepare iron-imido complexes by treatment of C PDI)-Fe(N2)2 ( PDI = (2,6- Pr2CgH3N = CMe)2C5H3N) with a series of aryl azides [47]. 

A first terminal imido complex of nickel (121) was prepared according to Equation (3).468 The synthesis goes via the Ni11 amido compound (122) and uses the steric bulk of the arylimido group for stabilization. The Ni11 center in (121) is planar and three-coordinate. Reaction of (121) with CO or benzyl isocyanide leads to formal nitrene transfer with formation of (124) and (125), respectively. Further reaction with CO liberates the isocyanate and carbodiimide (Equation (4)). 69... 

Inter- and intramolecular (cyclometallation) reactions of this type have been ob-.served, for instance, with titanium [408,505,683-685], hafnium [411], tantalum [426,686,687], tungsten [418,542], and ruthenium complexes [688], Not only carbene complexes but also imido complexes L M=NR of, e.g., zirconium [689,690], vanadium [691], tantalum [692], or tungsten [693] undergo C-H insertion with unactivated alkanes and arenes. Some illustrative examples are sketched in Figure 3.37. No applications in organic synthesis have yet been found for these mechanistically interesting processes. 

Synthesis and Characterization of Silica Supported Ta Imido Complexes... 

The addition of electrophilic agents to terminal nitride ligands can be applied to the synthesis of imido complexes. This has been demonstrated with triphenylcarbonium salts and compounds of the formula [Re NC(C6H5)3 X4] (X = C1, Br, F, NCS) have been studied by EPR spectroscopy and show similar spectroscopic features to their [Re NB(C6F5)3 X4] analogues. " ... 

Phosphinimato complexes transition metals, 122,125 bonding, 124 IR spectroscopy, 124 reactions, 125 structure, 124 synthesis, 123 Phosphini mines imido metal complexes synthesis from, 167 Phosphoglucomutase zinc complexes, 965 Phospholes... 

Sulfide oxidases, 773 Sulfinylamines imido metal complexes synthesis from, 167 Sulfites... 

Isocyanate formation through multiple bond metathesis of C02 with carbodiimide has been also demonstrated [112]. This transformation can be promoted by titanium isopropoxide, at 383 K, in THF as solvent. It is worth noting that the reverse process, which opens an entry into carbodiimide synthesis, is a well-known process that is catalyzed by several other systems, including trialkylphosphine oxides [113] or vanadium-oxo or -imido complexes [114]. 

Amidinato-amido chloro complexes, with Ti(IV), 4, 335-336 Amidinato-imido titanium complexes, synthesis, 4, 431 -32 Amidinato ligands... 

Bishomoallyl alcohols, via allyindium reagents, 9, 703 Bis(hydrostannation), in tin-carbon bond formation, 3, 814 Bis(imidazolyl) ligands, chromium complexes, 5, 359 Bis(imido) systems, with chromium(VI), as models, 5, 377 Bis(imido)tungsten complexes, synthesis, 5, 749 Bis(imido)uranium(VI) complexes, synthesis, 4, 216-217 Bis(imino)carbenes, with Zr(IV), 4, 798 Bis(iminooxazolidine) complexes, biaryl-bridged, with Zr(IV) and Hf(IV), 4, 811-812... 

Dibenzyl complexes with calcium, strontium, barium, 2, 120 with Ti(IV), 4, 343, 4, 349 with Zr(IV), 4, 783, 4, 785-786 with Zr(IV) mono-Cp complexes, 4, 833 Dibenzylgallium azides, for semiconductor growth, 12, 17 Dibenzyl imido complexes, with Ti(IV), 4, 352-353 Dibenzyl phosphoranimino carbenes, with Zr(IV), 4, 798 Dibenzyl titanasilsesquioxanes, synthesis, 4, 493 Dibenzyo-tetramethyltetraaza[14]-annulenes, with Zr(IV),... 

Imidazolium ligands, in Rh complexes, 7, 126 Imidazolium salts iridium binding, 7, 349 in silver(I) carbene synthesis, 2, 206 Imidazol-2-ylidene carbenes, with tungsten carbonyls, 5, 678 (Imidazol-2-ylidene)gold(I) complexes, preparation, 2, 289 Imidazopyridine, in trinuclear Ru and Os clusters, 6, 727 Imidazo[l,2-a]-pyridines, iodo-substituted, in Grignard reagent preparation, 9, 37—38 Imido alkyl complexes, with tantalum, 5, 118—120 Imido-amido half-sandwich compounds, with tantalum, 5,183 /13-Imido clusters, with trinuclear Ru clusters, 6, 733 Imido complexes with bis-Gp Ti, 4, 579 with monoalkyl Ti(IV), 4, 336 with mono-Gp Ti(IV), 4, 419 with Ru half-sandwiches, 6, 519—520 with tantalum, 5, 110 with titanium(IV) dialkyls, 4, 352 with titanocenes, 4, 566 with tungsten... 

Amino alcohol-N-oxides as precursors of chiral oxazolidines synthesis of (R)-(-)-cryp-tostyline I. Heterocycles 1993, 36, 1763-1769. Blum, S. A. Walsh, P. J. Bergman, R. G. Epoxide-opening and group-transfer reactions mediated by monomeric zirconium imido complexes./. Am. Chem. Soc. 2003, 325, 14276-14277. 

A convenient synthesis of zirconocene cyclic ester enolates such as complex 866 is the direct [2 + 4]-type cycloaddition reaction between the zirconocene imido complex and methyl methacrylate666 (Equation (52)). The resulting cyclic ester enolate can be activated by the Lewis acid A1(C6F5)3 for efficient polymerization of methyl methacrylate. 

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