Vanadium complexes amides

Another interesting asymmetric epoxidation technique using metal catalysis involves the vanadium complexes of A-hydroxy-[2.2]paracyclophane-4-carboxylic amides (e.g., 19), which serve as catalysts for the epoxidation of allylic alcohols with f-butyl hydroperoxide as... 

Comman, C.R., K.M. Geiser-Bush, and P. Singh. 1994. Structural and spectroscopic characterization of a novel vanadium(V)-amide complex. Inorg. Chem. 33 4621 -622. 

The first example of a /r-oxo-bis(/r-carboxylato)dioxovanadium(IV,V) complex has been reported (68).380 Coupling reactions have been used in the preparation of ligands containing amide groups. One condensation reaction led to the first structurally characterized, deprotonated vanadium(V)-amide product (69).381 This coordination mode was later observed for other amide... 

Comman CR, Zovinka EP, Boyajian YD, Geiser-Bush KM, Boyle PD, Singh P. 1995. Structural and EPR studies of vanadium complexes of deprotonated amide ligands effects on the V-51 hyperfine coupling constant. Inorg Chem 34 4213-4219. 

Various five-coordinate compounds are known for the configuration d of the oxovanadium(IV) and titanium(III). The complexes of the oxo-vanadium can have structures (more or less distorted) referable to the trigonal bip5n amid or more commonly to the square p n amid. 

R = R = Cy R = 1-adamantyl, R = CfiH 5. Te2-3,5 5 ). The vanadium analogue of the latter [V N(l-Ad)(C6H3Me2-3,5) 3] " 4 has also been characterized. Furthermore, a more efficient route to [Cr N(SiMe3)2 3] and a new crystal structure determination has been described. Three-coordinate metal amides have been treated in a general review that covers three-coordinate transition metal species with hard ligands. The electronic structure and bonding in tricoordinate amido complexes of transition metals have also been detailed... 

The monoammine complex K2[Os(NH3)C15], made by reduction of K[0s03N] with SnCl2 in HC166 or with vanadium(II) or europium(II),55 was once thought to be an amide, K2[Os(NH2)Cl5].67... 

Simple complexes of hydroxamic acids with vanadium(V) have been reported, including ones with a variety of nuclearities.249,250 A wide range of TV-substituted mono- and dihydroxamic acids undergo oxygen abstraction upon reaction with V111 and Vlv to form Vv hydroxamate complexes and the respective amides and diamides.251... 

A theoretical evaluation of ligands that would stabilize a vanadium-vanadium triple bond was undertaken and concluded that O- and N-donors in amidates would yield the greatest stability.890 A lantern-type metal-metal bonded dinuclear V11 complex was synthesized by the reduction of [VCl3(thf)3] with NaHBEt3 followed by addition of the lithium salt of V,V -di-p-tolylformamidate (215). 65 The crystal structure shows the V V distance to be 1.98 A, which is consistent with a fairly strong metal-metal triple bond.865... 

Vanadium(III) complexes, 473 adenine, 475 alcohols, 478 amides, 474, 480 amines, 474 amino acids, 484 ammonia, 474 aqua, 477 arsines, 476 azide, 475 bipyridyl, 475 bromides, 483 carboxylates, 479 catecholates, 478 chlorides, 482 complexones, 485 cyanides, 474,476 (Wethyl sulfoxide, 480 dioxygen, 478 dithiocarbamates, 481 dithiolates, 481 dithiophosphinates, 481 ethers, 478... 

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