Route organo-metallic

It is worth noting that in some cases adducts may be prepared by routes other than those leading directly to adduct formation. Thus Fraenkel and his co-workers139,140 obtained 4,4-dialkyl-substituted adducts from l-ethoxycarbonyI-4,4-dialkyl-l, 4-dihydropyridines by reaction with organo-metallic compounds, R M (M = Li, Na, K, MgX), according to Scheme 7. The NMR spectra of these adducts consisted of an AB system (J = 6.5-8.0 Hz). The chemical shift values were similar (Table XV) to those reported... 

Since plumbylene is a stable state in lead chemistry, oxidative addition of organo-metallics to plumbylene is an attractive way to lead-centered anions. Following this route, multidecker anions can be prepared for lead, if crown or cryptand ligands coordinate the alkali metal cations (equation 62)70. 

Preparation of metal nanorods covered by carbon has been reported in the recent literature.10-35 37 The organo-metallic precursor route provides a means of preparing... 

In a first approximation supra-Cp metal complexes can be prepared the same way as normal or other Cp-metal and organo-metal bonds in general. The methods used most often (see Appendix) are the metathesis reaction [Eq. (1)] followed in number by oxidative additions (Eq. (2)] and metallation/deprotonation reactions [Eq. (3)]. The latter is especially important for the cyclpentadienyl alkali metal compounds. A useful variation of reaction (3) is the formation of CpTl in an acid/base reaction from cyclopentadiene and thallium ethoxide [Eq. (3b)]. This represents a convenient route to cyclopentadienylthallium compounds, which are also valued (in place of Cp alkalis) as mild Cp-transfer reagents for the synthesis of difficultly isolable cyclopentadienyl derivatives (77). 

Organo-metallic or -metalloid reagents provide efficient routes to fluoroalkylated carbenes difluoromethylfluorocarbene (6.55A) is readily generated by a general route which involves the pyrolysis of fluoroaUcylsilicon compounds [84] (Figure 6.55). 

Production of ceramics by this novel route has a variety of advantages. First, much lower temperatures can be used, and higher purity products are obtained. Second, the microstructure of the ceramic can be better controlled, and it is relatively simple to form very thin ceramic coatings. Third, ceramic alloys are much easier to form by the hydrolysis of a mixture of organo-metallic materials, for example, silicates and titanates to give a Si02 Ti02 alloy. 

The coal sodium originally present as chloride and organo-metallic compounds is rapidly volatilized in the pulverized coal flame <23). Subsequently the volatile species are partly dissolved in the surface layer of flame heated silicate particles and partly sulphated in the flue gas (8). The formation of sodium sulphate can proceed via two routes ... 

The synthesis of isoquinoline by lithiation route is according to type C. Thus aromatic benzylamines or P-phenylethylamines are lithiated at ortho position. The organo-metallic compounds on treatment with epoxide or an aldehyde furnish ortho substituted compounds which are converted to isoquinolines... 

However, for less reactive monomers, catalysts are generally required. These compounds can activate the monomer, the initiator or both. Hedrick and co-workers were pioneers in this field because of the discovery and thus, the Introduction of a route towards metal-free polyesters [61-65]. Organo-catalytic polymerisations generally involve nucleophiles activating the monomer ring... 

A very versatile and easy entry into the chemistry of calixpyridines, recently reported, is predicated on the use of calixpyrroles as starting materials. This route, illustrated in Scheme 2, involves reaction of a calix[4]pyrrole with dichlorocarbene and provides a ready access into the previously unknown calix[3)pyridino[l]pyrrole and calix-[4]pyridine families. It also allows for the facile synthesis of calix[ I ]pyridino[3)pyrroles and calix(2Jpyridino[2Jpyr-roles, species that Floriani and coworkers have also produced from calix(4]pyrroles using alternative organo-metallic-based procedures. ... 

From bis-silanol monomers, themselves prepared either via an organo-metallic route or via hydrosilylation of a,c -dienes. The bis-silanol monomers are then polymerized to give hybrid homopolymers or condensed with difunctional silanes to give copolymers (cf Scheme 2). 

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