Organic halides defined

This simple example may illustrate that in general the reaction of an organic halide salt [cation]X with an excess of a Lewis-acid MXy can result in new catalytic materials even if other Lewis-acids are applied than AICI3. In contrast, the use of other Lewis-acids to form the ionic liquid of type [cation][MXy+i] + excess MXy (the excess of MXy may be dissolved in the neutral ionic liquid or may form acidic anionic species such as e.g. [M2X2y+i]-) gives access to new combinations of properties (e.g. a liquid, less oxophilic, Lewis-acidic catalyst with defined solubility and acidity properties). In Table 2 other examples of ionic liquids are presented which are formed by the reaction of an organic halide salt with different Lewis-acids. All these systems should be in principle useful acidic catalysts for synthetic organic chemistry even if not all displayed examples have been already discribed in the literature for this application. 

Draw the structure of chlorobenzene, CeHsCl, an aromatic organic halide. (Organic halides are defined in Section 20.3.)... 

The Type I Ac-Pd reactions of internal alkene-containing organic halides are generally more favorable and predictable (Scheme 52) [67,110,111]. In cases where the alkenyl group is stereo defined, the Type I Ac-Pd reaction is not stereospecific but stereoselective, favoring the E isomer. 

The Barbier reaction will be defined in the classic sense and will include any one of the following reaction sequences (1) addition of an organic halide to a mixture of magnesium and an electrophilic coreactant such as a ketone, (2) addition of a mixture of an organic halide and coreactant, over time, to magnesium, or (3) the combination of all three reagents at once. 

The cross-couphng reaction is arbitrarily defined as a process of single carbon-carbon bond formation between two unlike carbon groups by reaction of an organometallic species with an organic halide or a related electrophihc derivative (Scheme 3.127). 

Poly(V-vinyl-2-pyrrolidone) has been studied as a carrier for palladium in the hydrogenation of oleflns f and nitroaromatics, hydrodehalogenation of organic halides,f t and carbonylation of aUyl halides. - In these cases PVP mostly likely played the role of supporting in situ formed colloidal Pd, rather than that of a well-defined ligand. 

Finally, the sum of those organic halides that are extracted from solids is defined as extractable organic halide (BOX) [154]. EOXs containing chlorine, bromine, or iodine are... 

A major improvement from a preparative point of view was demonstrated by Mizoroki, Heck, and colleagues, who independently found that organic halides were suitable organopalladium precursors, and that the vinylic substitution reaction could be accomplished with a catalytic amount of palladium and a base, in the absence of a reoxidantThis reaction was developed further by Heck and co-woikers and was later referred to as the Heck reaction or Heck oleflnationJ f The Heck reaction is defined as a vinylic substitution reaction where a vinylic hydrogen is substituted by an aryl, vinyl, or benzyl group (Scheme 2). 

Heck Reaction. The Heck reaction may be defined as the Pd-catalyzed substitution of an alkenyl hydrogen with a carbon group of organic halides and related electrophiles. Although Cl2Pd(PPh3)2 has not been widely used in the Heck reaction, it does appear to be a satisfactory catalyst, as indicated by the following examples (eqs 30 and 31). 

Now that many facile controlled/living radical polymerization systems have been developed for a wide range of monomers, many researchers have adopted them as a tool for preparing well-defined stmcture polymers not only in polymer chemistry ° but also in the biochemical, medical, and optoelectronic fields. Among the various radical polymerization systems, the transition metal-catalyzed atom transfer process is one of the most promising processes in terms of controllability, facility, and versatility. In this reaction, one polymer chain forms per molecule of organic halide as an initiator, while a catalytic amount of the metal complex serves as an activator, which would homolytically cleave the carbon-halogen terminus (Scheme 1). 

The Friedel-Crafts alkylation of aromatic compounds with alkyl halides in the presence of Lewis acid is well defined in organic chemistry. However, alky-... 

In a similar way, the formation of halide complexes with other jt-acceptors in Fig. 3 are revealed by the appearance of new absorption bands in the electronic spectra to reflect the yellow to red colorations of the mixtures. The spectral data thus indicate that halide salts form well-defined electron donor/acceptor complexes with organic jt-acceptors, as typified by Eq. 2 ... 

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