Synthesis applications with antimony

Only one isolated example of formation of thioketene and thioaldehyde dimolybdenum complexes has been reported507, but in contrast, zirconocene thioacetaldehyde and thiobenzaldehyde complexes, introduced by Buchwald, have been the subject of several studies508, including their application in the synthesis of novel antimony thiametallacy-cles 148509 (equation 156). Compound 146 was generated in situ and, after reaction with alkynes, gave rise to metallacycles 147 which, by treatment with SbCR, afforded 148. 

Covalent fluondes of group 3 and group 5 elements (boron, tin, phosphorus, antimony, etc ) are widely used m organic synthesis as strong Lewis acids Boron trifluoride etherate is one of the most common reagents used to catalyze many organic reactions. A representative example is its recent application as a catalyst in the cycloadditions of 2-aza-l,3-dienes with different dienophiles [14] Boron trifluoride etherate and other fluonnated Lewis acids are effective activators of the... 

What about the applicability of organolithium compounds of type 29 with heavy organoelement groups in organic synthesis At present we can realize three modes of use (Scheme 39). The antimony compound is suitable as a reagent for nucleophilic halomethylation Nucleophilic lithiomethylation and carbonyl olefination, two other modes of application, are the objects of Sects. 4.4,4.5, and Chap. 5. 

The well known ability of antimony pentafluoride to oxidize some elements, such as sulfur or selenium, to the corresponding polynuclear cations [1] found its application in the synthesis of fluorinated materials. Reaction of sulfur with TFE, HFP, and PFIB in the presence of SbF5 was reported [ 129,130] ... 

Although Mossbauer spectroscopy is a technique that is relatively little used in catalysis, it has yielded very useful information on a number of important catalysts, such as the iron catalyst for Fischer-Tropsch and ammonia synthesis, and the cobalt-molybdenum catalyst for hydrodesulfurization reactions. The technique is limited to those elements that exhibit the Mossbauer effect. Iron, tin, iridium, ruthenium, antimony, platinum and gold are those relevant for catalysis. Through the Mossbauer effect in iron, one can also obtain information on the state of cobalt. Mossbauer spectroscopy provides valuable information on oxidation states, magnetic fields, lattice symmetry and lattice vibrations. Several books on Mossbauer spectroscopy [1-3] and reviews on the application of the technique on catalysts [4-9] are available, with Millet s [9] review being the most recent at the time of writing this revision. 

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