Acyl nitrates initiators

Poly(azophenylene-o-carborane) (see 6) has been prepared from diphenyl-o-carborane by means of nitration, reduction, and acylation to initially give 1,2-bis(/ -nitroso-acetylaminophenyl)-o-carborane (NAFC). Rapid decomposition in solution affords phenylene amino phenyl carborane (PAFC) by recombination of phenylene and azophenylene radicals.40 These radicals have also been utilized to form copolymers of carborane-containing copolymers from monomers polymerizable via radical mechanisms. Thus, copolymers of polystyrene and poly(azophenylene) can be readily formed by means of emulsion copolymerization of styrene with NAFC decomposition products. 

In numerous chemical reactions, ionic species are formed as intermediates which are subsequently converted into more stable, neutral, reaction products. Examples are provided by numerous well-known substitution reactions such as Friedel-Crafts acylations, nitration reactions, or chlorination reactions. The initial steps of these reactions are completely analogous to reactions of type (3) or (4). 

The oxidation reactions of aldehydes with OH in the presence of NOx are very important from the point of forming peculiar compoimds with strong biological toxicity called peroxy acyl nitrates (PANs, RC(0)00N02). The initial reaction of OH and aldehydes are H-atom abstraction forming the aldehyde group to form acyl radicals as seen in Chap. 5, Sect. 5.2.11. For example, in the case of acetaldehyde, the reaction mechanism is. 

Biphenyl and terphenyls may be regarded as substituted benzenes that undergo acylation, alkylation, halogenation, nitration, sulfonation, and other reactions common to benzene. The points of initial attack on chlorination, miration, and sulfonation of biphenyl occur at the 2- and 4-positions the latter group predominates. 

Substituent(s) Bro initiation Nitration Formylation acylation rearrangement rearrangement reactions Ref. 

Nitration, halogenation, sulphonation, alkylation and acylation are examples of aromatic electrophilic substitution. These reactions are initiated either by electrophiles or substances which produce electrophilic species. 

Suspension polymerization was applied to prepare polynor-bomene aosslinked beads suitable for use as supports in organic synthesis. The monomers used included norbor-nene, norbom-2-ene-5-methanol, and aosslinking agents including bis(norbom-2-ene-5-methoxy)alkanes, di(norbom-2-ene-5-methyl)ether, and l,3-di(norbom-2-ene-5-methoxy) benzene. The initial resins, which were unsaturated, were subsequently modified using hydrogenation, hydrofluorination, chlorination, or bromination to yield saturated resins with varying properties. They were reported to be superior to more traditional styrene-divinylbenzene resins due to reduced interference in electrophilic aromatic substitution reactions (e.g., Friedel-Crafts acylation and nitration). 

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