Molybdenum complexes, carbonyl

A structural study of a molybdenum carbonyl complex of phosphabenzene has shown that the phosphorus is a-bonded to the... 

Selected examples of the conversion of benzyl chlorides into arylacetic acids and arylpyruvic acids using molybdenum carbonyl complexes ... 

Analogous carbonylation reactions using nickel and iron carbonyl based systems also produce alkanecarboxylic acids [11, 13, 14]. The mechanism of the conversion of benzyl halides into arylacetic acids using iron pentacarbonyl is not as well defined as it is for reactions promoted by nickel or molybdenum carbonyl complexes. Iron... 

Hi) Formation of transition metal carbonyl complexes Ashe and Colburn have reported (77JA8099) the synthesis of molybdenum carbonyl complexes of arsenin and antimonin but were unable to prepare bismin complexes because of its lability (Scheme 23). As expected for electron-rich aromatic compounds, both formed six-electron 7r-complexes (113) by a ligand displacement mechanism. Arsenin also forms a two-electron complex (114) analogous to those formed by pyridine, whereas antimonin did not give a similar complex under the conditions of this reaction. 

Support-bound transition metal complexes have mainly been prepared as insoluble catalysts. Table 4.1 lists representative examples of such polymer-bound complexes. Polystyrene-bound molybdenum carbonyl complexes have been prepared for the study of ligand substitution reactions and oxidative eliminations [51], Moreover, well-defined molybdenum, rhodium, and iridium phosphine complexes have been prepared on copolymers of PEG and silica [52]. Several reviews have covered the preparation and application of support-bound reagents, including transition metal complexes [53-59]. Examples of the preparation and uses of organomercury and organo-zinc compounds are discussed in Section 4.1. 

Scheme 2.29 depicts two of the first examples of microwave-assisted carbonylation reactions7. In these reactions, the temperature controls the rate of the CO release. Thus, during heating at 150°C in sealed vessels, carbon monoxide was smoothly emitted from the molybdenum carbonyl complex into the reaction mixture (Fig. 2.1, Profile A). As a result, aryl iodides and bromides underwent efficient amino carbonylation with non-hindered, aliphatic, primary and secondary amines in only 15 min, using Herrmann s palladacycle as pre-catalyst7 (Scheme 2.29). In contrast, at a reaction temperature of 210°C, carbon monoxide was liberated almost instantaneously (Fig. 2.1, Profile B).

Metallacumulenes with alkylidynes, 5, 458-459 in molybdenum carbonyl complexes, 5, 401 Metallacycles with bis-Gp Ti(IV), 4, 563 with nickel... 

Merlic, CA. and Adams, B. (1992) Molybdenum-95 nuclear magnetic resonance studies on molybdenum carbonyl complexes of isonitriles and amines./. Organomet. Chem., 431, 313-325. 

Molybdenum carbonyl complexes useful for inhibiting tumour necrosis factor (TNF) production and for treating inflammatory diseases [242]... 

Molybdenum carbonyl complexes for treating rheumatoid arthritis and other inflammatory diseases [208]... 

The use of CO-releasing molybdenum carbonyl complexes for the treatment of inflammatory diseases [188]... 

Romao CC, Rodrigues SS, Seixas JD, Pina ARM, Roya B, Fernandes AC, Goncalves I, Haas W (2007) Method using CO-releasing molybdenum carbonyl complexes for the treatment of inflammatory diseases. Patent WO 2007/073226... 

Aside from the structure obtained for 1-chloroborepin referred to in Section 14.20.3.3, no other X-ray studies of simple borepins or benzoborepins have been reported however, an X-ray structure for molybdenum carbonyl complex 12 has been obtained <19970M1884> and was compared to previously reported structures for 13 and 14 <1992AGE1255> shown in Figure 3. 

Similarly, orange-red needles (mp 53 °C) of 1-fluoroborepin molybdenum carbonyl complex 18 were obtained by conversion of 1-methoxyborepin 17 to the corresponding Mo(CO)3 complex followed by immediate treatment of the crude complex with boron trifluoride in pentane, as in Scheme 1. The intermediate molybdenum complex of 17 could be isolated as air- and moisture-sensitive crystals (mp 110-115 °C) but prolonged manipulation led to contamination by the corresponding 1-hydroxyborepin complex <19970M1884>. 

Molybdenum carbonyl complexes of cyclotriphosph-(in)azanes, [(RO)PNEt]3 (R = CH2CF3 or C6H3Me2-2,6) and metal complexes of [ArOPNEt]3 (Ar = 2,6-Pr2C6H3) have been described. 

The simplicity and power of this approach, known as the method of local oscillating dipoles, was first demonstrated by Orgel (111), who used it to assign the spectra of octahedral molybdenum carbonyl complexes. Very similar arguments were presented simultaneously, but independently, by El-Sayed and Kaesz (59) in a discussion of the spectra of pentacarbonyl halide derivatives of Group VIIA metals. Subsequently, the model has been applied to the assignment of bands in the spectra of numerous octa-... 

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