Primary Reactions

Other Reactions. Primary amyl alcohols can be halogenated to the corresponding chlorides by reaction with hydrogen chloride in hexamethylphosphoramide (87). Neopentyl chloride [753-89-9] is formed without contamination by rearrangement products. A convenient method for preparing / f/-amyl bromide and iodide involves reaction of / f/-amyl alcohol with hydrobromic or hydroiodic acid in the presence of Li or Ca haUde (88). The metal haUdes increase the yields (85 —95%) and product purity. 

Organic Reactions. Primary alcohols react with sulfamic acid to form alkyl ammonium sulfate salts (21—23) ... 

The mechanism of the alkoxymercuration reaction is similar to that described in Section 7.4 for hvdroxymercuration. The reaction is initiated by electrophilic addition of Iig2+ to the alkene, followed by reaction of the intermediate cation with alcohol and reduction of the C-Hg bond by NaBH4. A variety of alcohols and alkenes can be used in the alkoxymercuration reaction. Primary, secondary, and even tertiary alcohols react well, but ditertiary ethers can t be prepared because of steric hindrance to reaction. 

Secondly, it has been found that the benzidine rearrangement is subject to a solvent isotope effect d2o/ h2o > 1- If a proton is transferred from the solvent to the substrate in a rate-determining step the substitution of protium by deuterium will lead to a retardation in the rate of reaction (primary isotope effect) whereas if a proton is transferred in a fast equilibrium step preceeding the rate-determining step as in... 

The reaction of naphthols with ammonia and sodium bisulfite is called the Bucherer reaction. Primary amines can be used instead of ammonia, in which case N-substituted naphthylamines are obtained. In addition, primary naphthylamines can be converted to secondary, by a transamination reaction ... 

In a related reaction, primary aromatic amines have been oxidized to azo compounds by a variety of oxidizing agents, among them Mn02, lead tetraacetate, O2 and a base, barium permanganate, and sodium perborate in acetic acid, tert Butyl hydroperoxide has been used to oxidize certain primary amines to azoxy compounds. 

Another reagent that convert benzylic halides to aldehydes is pyridine followed by /7-nitrosodimethylaniline and then water, called the Krohnke reaction. Primary halides and tosylates have been oxidized to aldehydes by trimethylamine N-oxide, and by pyridine N-oxide with microwave irradiation. ... 

Post-inflammatory hyperpigmentation (PIH) is the acquired presence of darker macules and patches of skin occurring at sites of previous cutaneous inflammatory conditions. The processes preceding the altered skin color include mechanical injuries, allergic reactions, primary inflammatory skin disorders, and therapeutic interventions. 

In electroanalysis, coulometry is an important method in which the analyte is specifically and completely converted via a direct or indirect electrolysis, and the amount of electricity (in coulombs) consumed thereby is measured. According to this definition there are two alternatives (1) the analyte participates in the electrode reaction (primary or direct electrolysis), or (2) the analyte reacts with the reagent, generated (secondary or indirect electrolysis) either internally or externally. 

Active transport. The definition of active transport has been a subject of discussion for a number of years. Here, active transport is defined as a membrane transport process with a source of energy other than the electrochemical potential gradient of the transported substance. This source of energy can be either a metabolic reaction (primary active transport) or an electrochemical potential gradient of a substance different from that which is actively transported (secondary active transport). 

Antioxidants act so as to interrupt this chain reaction. Primary antioxidants, such as hindered phenol type antioxidants, function by reacting with free radical sites on the polymer chain. The free radical source is reduced because the reactive chain radical is eliminated and the antioxidant radical produced is stabilised by internal resonance. Secondary antioxidants decompose the hydroperoxide into harmless non-radical products. Where acidic decomposition products can themselves promote degradation, acid scavengers function by deactivating them. 

The polymerization of 1-olefins introduces the problems of regioselectivity and stereoselectivity. In this section we will focus on the origin of the regioselectivity of the insertion reaction (primary vs. secondary 1-propene insertion, see Figure 9), while the origin of the stereoselectivity will be discussed in the next section. 

RCH200 + RCH2Hal -> RCH2-OO-CH2R + HaE. Reactions of KO2 with optically active alkyl halides proceed with the configurational inversion. Moreover, the reactivity changes in the same order as that of the usual Sj. 2 reactions (primary > secondary > tertiary J > Br > Cl) (Sawyer and Gibian 1979). 

With ketone donors, both syn and anti selective reactions are possible. Typically, a,p-unsaturated nitro compounds are used as acceptors. The majority of these reactions are syn selective (Scheme 28) [94, 269, 271, 278, 279, 288-309]. This is a result of favored formation of the (fj-configured enamine and favorable electrostatic interactions between the nitro group and the enamine (Scheme 29) [290, 291, 310]. Of the known anti selective reactions, primary amine-thiourea catalysts such as 158 appear to perform best (Scheme 28) [271, 299, 301]. 

Fullerenes can also be obtained by pyrolysis of hydrocarbons, preferably aromatics. The first example was the pyrolysis of naphthalene at 1000 °C in an argon stream [58, 59], The naphthalene skeleton is a monomer of the Cjq structure. FuUerenes are formed by dehydrogenative coupUng reactions. Primary reaction products are polynaphthyls with up to seven naphthalene moieties joined together. FuU dehydrogenation leads to both Cjq as well as C7Q in yields less than 0.5%. As side products, hydrofuUerenes, for example CjqHjj, have also been observed by mass spectrometry. Next to naphthalene, the bowl-shaped corannulene and benzo[k]fluoranthene were... 

Meyers and Shimano further expanded the scope of this methodology to include lithium amides as the nucleophile. The authors meticulously optimized the reaction conditions and determined the scope of the amide addition. Selected examples are listed in Table 8.32 (Scheme 8.163). The best results were obtained when THF was used as the solvent together with a stoichiometric amount of HMPA, relative to the lithium amide. The reaction was quite sensitive to the steric demand of the amide. Thus, lithium diethylamide give no product whereas lithium methyl n-pentylamide and lithium piperidide gave efficient reaction. Primary amides also failed to react. 

Dermatitis Inflammation of die skin from any cause. There are two general types of skin reaction primary irritation dermatitis and sensitization dermatitis. 

The half-life with respect to chemical transformation of CH3I in seawater at 20°C was determined to be 20 days, as compared to about 200 days in freshwater (reaction with H20 yielding CH3OH). In a case of a groundwater contamination with several alkyl bromides, Schwarzenbach et al. (1985) reported the formation of dialkyl sulfides under sulfate-reducing conditions in an aquifer. They postulated that in an initial reaction, primary alkyl bromides reacted with HS" by an SN2 mechanism to yield the corresponding mercaptans (thiols) ... 

In summary, protein molecules may contain up to nine amino acids that are readily derivatizable at their side chains aspartic acid, glutamic acid, lysine, arginine, cysteine, histidine, tyrosine, methionine, and tryptophan. These nine residues contain eight principal functional groups with sufficient reactivity for modification reactions primary amines, carboxylates, sulfhydryls (or disulfides), thioethers, imidazolyls, gua-nidinyl groups, and phenolic and indolyl rings. All of these side chain functional groups in addition to the N-terminal a-amino and the C-terminal a-carboxylate form the full complement of polypeptide reactivity within proteins (Fig. 12). 

Besides the advantage of their high reactivity toward alkylation reactions, primary and secondary alkyl halides show little tendency for dehydrohalogenation in Nafion-H-catalyzed gas-phase reactions.235 Although a minor amount of olefin is reported to be formed, no polymer formation was observed on the catalyst. As a result, the catalytic activity of Nafion-H stays constant over prolonged on-stream periods. 

Amides. Primary amides exhibit behaviour similar to the corresponding acid and methyl esters substituted amides resemble the higher alkyl esters. There is a common tendency to form M + 1 ions by ion-molecule reactions. Primary amides generally give a strong peak at m/z 44 ... 

In these alkylation reactions primary alkyl halides (the bromide for preference) should be used as the alkylating agents, since secondary and tertiary halides undergo extensive olefin-forming elimination reactions in the presence of the strongly basic acetylide ion. A typical synthesis is that of hex-l-yne (Expt 5.26). 

Modified Hunsdiecker reaction. Primary carboxylic acids are converted into thallium(I) carboxylates by reaction with T12C03. The salts are not isolated, but treated with Br2 (1.5 equiv.) to give primary alkyl bromides (equation I).1... 

Figure 2.2 Theoretical kinetic curves for interfering reactions (primary 1 and secondary 2) of extreme (a) and asymptotic (b) type A is the phase shift.

Scheller 17 modified the Bart reaction to such an extent that his method is often referred to as the Scheller reaction. Primary aromatic amines, dissolved in methanol or glacial acetic acid, are diazotized in the presence of arsenic trichloride and a trace of cuprous chloride. Removal of the solvent followed by treatment with water and sodium hydrosulfite gives the expected arsonic acids. 

For synthesis of an unsymmetrical ether, the most hindered alkoxide should be reacted with the simplest alkyl halide rather than the other way round (Following fig.). As this is an SN2 reaction, primary alkyl halides react better then secondary or tertiary alkyl halides. 

The chemical selectivity of reactions catalyzed by supported TEMPO closely resembles the patterns observed for homogeneous reactions. Primary alcohols are strongly preferred over secondary alcohols. Especially in liquid biphasic systems, high aldehyde yields can be achieved with as little as 0.1 mol% of the immobilized catalyst (412) ... 

In the palladium-catalyzed allylic amination reaction, primary and secondary amines can be used as nucleophiles, whereas ammonia does not react. Therefore, many ammonia synthons have been developed, and a variety of protected primary allyl amines can now be prepared using azide, sulphonamide, phthalimide, di-f-butyl iminocarbonate ((Boc)2NLi), and dialkyl A-(rerr-butoxycarbonyl)phosphoramide anions as the nucleophile [20], An example of the use of ((Boc)2NLi) 30 as the amine nucleophile in the palladium-catalyzed allylic amination reaction is shown in Eq. (9). This reaction also illustrates the problem with the regioselectivity in the reaction as a mixture of the products 31-33 are obtained [21]. 

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