Molybdenum carbonyl preparation

The MofVJ compounds [Mo(R2cffc)4]X can be prepared by oxidative addition of thiuram disulfide to molybdenum carbonyls or by mild oxidation of Mo(R2C fc)4. 

MOLYBDENUM CARBONYL-CATALYZED ALKYNOL CYCLOISOMERIZATION PREPARATION OF 2-PHENYL-2,3-DIHYDROFURAN (Furan, 2,3-dihydro-2-phenyl-)... 

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. 

The photochemical synthesis of the tungsten carbonyl metallocarborane [Eq. (18) ] is also effective in the preparation of the molybdenum carbonyl analog. The resulting air-sensitive complexes show chemical behavior similar to the cyclopentadienyl analogs, C5H5M(CO)3, in that they undergo protonation with anhydrous HOI and met.hylation with CH3I. They also react further with metal hexacarbonyls to afford bimetallic complexes 54) ... 

Cyclohexadiene-Mo(CO)iCp complexes. The molybdenum complex 1 is prepared from 3-bromo-1-cyclohexene by reaction with molybdenum carbonyl and lithium cyclo-pentadienide followed by hydride abstraction. It undergoes a highly regio- and stereoselective reaction with a Grignard reagent to gi c an adduct (2) with an axial substituent... 

Cycloheptatrienemolybdenum tricarbonyl has been prepared by refluxing cycloheptatriene with molybdenum hexacarbonyl in benzene. It is a convenient starting material for the preparation of trisubstituted molybdenum carbonyls and of tropyliummolybdenum carbonyl salts. ... 

S. Tangestaninejad, M. H. Habibi, V. Mirkhani, M. Moghadam, G. Grivani, Readily prepared polymer-supported molybdenum carbonyls as novel reusable and highly active epoxidation catalysts, Inorg. Chem. Commun. 9 (2006) 575. 

Studies performed in previous years (ref.3-5) over molybdenum loaded zeolites in HDS reaction showed that reactivity of these catalysts depends on the type of zeolite used, concentration of transition metal and the way of preparation. However, preparation of molybdenum based catalysts applying ammonium heptamolybdate usually results in low dispersion of molybdenum sulfides and relatively low activity. Recent studies showed that saturation of Y-zeolites with molybdenum carbonyl can produce catalysts with high molybdenum dispersion (ref.6, 7). Subsequent sulfidation of these catalysts leads toward highly dispersed, supported sulfided molybdenum species (ref. 8,9) exhibiting high reactivity in HDS and water-gas shift reaction (ref. 9,10). 

Besides exotic ring shapes, 1980 has not seen the neglect of exotic heteroatoms, (453) ° represents three crown compounds, which were prepared by conventional means, thoroughly investigated and their stereochemistries deduced via their molybdenum carbonyl complexes. 

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