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Allyl complexes overview

The most widely used application of nickel-diene complexes is the dimerization of 1,3-dienes. Pioneering studies hy WiUce demonstrated many different modes of coupling, including dimerization, trimerization, and oligomerization of 1,3-dienes.l An overview of the product classes that maybe obtained from 1,3-dienes is provided in Scheme 4 (see also Houben-Weyl, Vol. E18, pp 93 and 932-937). The initially formed nickel complexes 5 and 6 have not been isolated. However, the complexes may be stabilized by the addition of phosphines, and jr-allyl complexes 7-9 have been prepared and characterized. [Pg.9]

Abstract The purpose of this chapter is to present a survey of the organometallic chemistry and catalysis of rhodium and iridium related to the oxidation of organic substrates that has been developed over the last 5 years, placing special emphasis on reactions or processes involving environmentally friendly oxidants. Iridium-based catalysts appear to be promising candidates for the oxidation of alcohols to aldehydes/ketones as products or as intermediates for heterocyclic compounds or domino reactions. Rhodium complexes seem to be more appropriate for the oxygenation of alkenes. In addition to catalytic allylic and benzylic oxidation of alkenes, recent advances in vinylic oxygenations have been focused on stoichiometric reactions. This review offers an overview of these reactions... [Pg.217]

Summary Two catalytic reactions, i.e. silylative coupling (mms-silylation) (SC) catalyzed by complexes containing or generating Ru-H and/or Ru-Si bonds (I, II, V, VI) and cross-metathesis (CM) catalyzed by mthenium-carbene (i.e. 1st and 2nd generation mthenium Grubbs catalyst (ID, IV)) of vinyl and allyl-substituted hetero(N,S,B)organic compounds with conunercially available vinyltrisubstituted silanes, siloxanes, and silsesquioxane have been overviewed. They provide a universal route toward the synthesis of well-defined molecular compounds with vinylsilicon functionality. [Pg.416]

Aromatic organosulfur compounds such as thiophenes, benzothiophenes and dibenzothiophenes are frequently contained in fossil oil and their sulfur atoms are generally difficult to remove in HDS process [106], In the industrial HDS process, Mo/Co/S or Ni/Mo/S heterogeneous catalysts supported on alumina are widely employed. In order to obtain ideas to develop more efficient catalysts as well as to shed some light on their mechanisms at a molecular level, transition metal complex-mediated cleavages of C-S bond are extensively studied. On the other hand, thiiranes and thietanes are frequently employed for preparation of transition metal sulfides, in which their C-S bonds are smoothly cleaved. In this section, the C-S bond cleavages of thiophene derivatives, thiiranes, thietanes, vinylic sulfides, allylic sulfides, thiols and dithioacetals are overviewed. [Pg.150]

Phosphorus-Based Polymers From Synthesis to Applications aims at providing a broad overview of recent developments in the synthesis and applications of phosphorus-containing polymers. Over the last few years, more and more research papers have been published on this field. Polymerization of different kinds of phosphorus-based monomers using various methods has been carried out (meth)acrylates, (meth)acrylamides, vinylphosphonic acid, styrenic, and allylic monomers. The resulting phosphorus-based materials have found applications in different domains biomedical, complexation with metals, fire retardant additives, fuel cell membranes, etc. [Pg.5]

Myrcene is a very abundant acyclic monoterpene available from the essential oils of various plants including wild thyme and hops. Recently, an excellent overview on the manufacture and transformation of this natural product was given by Behr and Johnen [125]. Commercially, myrcene is produced by the pyrolysis of pinenes [126]. The rhodium-catalyzed hydroformylation of myrcene gives usually a mixture of fragrance aldehydes in more than 90% combined yields (Scheme 6.37) [127, 128]. The main aldehyde, which accounted for 70 - 80% of the mass balance, results from the reaction with the less substituted C=C bond through the formation of a T) -allyl rhodium intermediate complex [127]. The reaction was also performed in a toluene/water biphasic system using the water-soluble TPPTS ligand and a cationic surfactant [84]. [Pg.552]


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See also in sourсe #XX -- [ Pg.104 ]




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