Group acidic hydrocarbons

Group V. Hydrocarbons and compounds containing C, H and 0 that are not in Groups I-IV and are soluble in concentrated sulphuric acid ( indifferent compoimds ). 

Reactions other than those of the nucleophilic reactivity of alkyl sulfates iavolve reactions with hydrocarbons, thermal degradation, sulfonation, halogenation of the alkyl groups, and reduction of the sulfate groups. Aromatic hydrocarbons, eg, benzene and naphthalene, react with alkyl sulfates when cataly2ed by aluminum chloride to give Fhedel-Crafts-type alkylation product mixtures (59). Isobutane is readily alkylated by a dipropyl sulfate mixture from the reaction of propylene ia propane with sulfuric acid (60). 

The acid number is mainly defined for rosins and rosin-derived resins and for phenol-modified resins. Standard hydrocarbon resins have zero acid number because the absence of functional groups. However, the acid number allows one to control deterioration by oxidation with formation of carbonyl and carboxyl groups in hydrocarbon resins. Typical acid number values of different resin types are ... 

The formation enthalpies of a few acids and parent hydrocarbons are given in Table 1.6. The oxidation of the methyl group of hydrocarbon to carboxyl group is a highly exothermic reaction. The enthalpy of the reaction... 

In trifluoroacetic acid [0.4 M TBABF4 (tetrabutyl ammonium tetrafluoroborate)] unbranched alkanes are oxidized in fair to good yields to the corresponding triflu-oroacetates (Table 2) [16]. As mechanism, a 2e-oxidation and deprotonation to an intermediate carbenium ion, that undergoes solvolysis is proposed. The isomer distribution points to a fairly unselective CH oxidation at the methylene groups. Branched hydrocarbons are preferentially oxidized at the tertiary CH bond [17]. 

Standard organolithium reagents such as butyllithium, ec-butyllithium or tert-butyllithium deprotonate rapidly, if not instantaneously, the relatively acidic hydrocarbons of the 1,4-diene, diaryhnethane, triarylmethane, fluorene, indene and cyclopentadiene families and all terminal acetylenes (1-alkynes) as well. Butyllithium alone is ineffective toward toluene but its coordination complex with A/ ,A/ ,iV, iV-tetramethylethylenediamine does produce benzyllithium in high yield when heated to 80 To introduce metal into less reactive hydrocarbons one has either to rely on neighboring group-assistance or to employ so-called superbases. 

Organic gases Hydrocarbons Aldehydes, ketones Other organics Benzene, butadiene, butene, ethylene, isooctane, methane Acetone, formaldehyde Acids, alcohols, chlorinated hydrocarbons, peroxyacyl nitrates, polynuclear aromatics There are two main groups of hydrocarbons of concern volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). 

Acids Hydrocarbons with a hydrogen replaced by a carboxyl (COOH) group. In solution, acids can release a hydrogen ion COOH - COO- + H+. 

XS = sulfonation, M = methylolation, MO = miscellaneous oxidation, G = grafting, P = phenolation, CM = carboxymethylation, MAC = maleic anhydride copolymerization, MCR = miscellaneous carboxyla-tion reactions, E = epichlorohydrin (also in conjunction with pheno-lated lignin), A = alkoxylation (i.e., ethylene, propylene, and butylene oxides), M+EP = modification with compounds containing unsaturated end groups ( divalent hydrocarbons ) followed by epoxidation with peroxide, MA = methacrylic acid. 

An electropositive metal in organic compounds of alkali metals is replaced by a more electropositive one in series of reversible reactions. More electronegative, i. e. more acid, hydrocarbon groups or whole molecules replace those which are less acid [140]. Caesium replaces lithium in ethyllithium. Benzene, which is a stronger acid than ethane, replaces ethyl in ethyllithium. Toluene and H2 are more acid than benzene, and they can therefore replace phenyl in phenylsodium [141, 142],... 

Transfer of two hydride ions and one proton would result in DMH. Since the methyl groups could migrate on the chain, DMH s other than 2,5-DMH could be produced. Some t-butyl cations dissociate into isobutylene and protons hence this method could occur during alkylation with olefins other than isobutylene. Reaction N is probably only of minor Importance in most cases, however, since only small concentrations of free isobutylene are thought to occur at the acid-hydrocarbon interface most isobutylene quickly protonates to form t-butyl cations. 

In the absence of activating unsaturated groups the hydrocarbons are exceedingly weak acids. The direct measurement of pA in such cases has not been achieved. Reversible electrode potentials have been used in conjunction with bond-dissociation energies via thermodynamic cycles (30-31) to estimate... 

Carbonyl compounds are reduced to symmetrical ethers, probably by way of reduction of some of the starting material to a silyl ether (9), reaction to form the mixed ketal (10) and then reductive replacement of the silyloxy group. Some hydrocarbon may be obtained as a by-product by reduction of (9 Scheme 4). Among the acid partners that have been used are trifluoroacetic acid, trityl perchlorate (with aldehydes) and electrogenerated protons. With Nafion resin symmetrical ethers are obtained from aldehydes, but silyl ethers are obtained from ketones. ... 

Lithium metal may react with acidic hydrocarbons to give organolithiums. This reaction also occurs with other alkali metals, more commonly with the heavier group-IA metals potassium and Cs (see 5.5.3.2.4). Usually, deprotonation of acidic hydrocarbons ( 5.5.2.3.2) is the method of choice for organolithiums from acidic hydrocarbons, but in special cases where contaminants must be avoided, the direct reaction with Li metal can be useful. 

Group-IA organometallics are formed from acidic hydrocarbons with more basic organometallic in acid-base or metallation reactions ... 

Group-IA alkoxides metallate acidic hydrocarbons. These bases are available commercially or are prepared from the metal with an alcohol. The nonnucleophilic (CH3)3C0K is the most widely used. 

Carbon-Group-IIB Bonds 5.7.2.S. from Metal Salts S.7.2.3.4. with Acidic Hydrocarbons. 

Organo-Zn, -Cd and -Hg derivatives can be prepared from other compounds by proton-metal exchange with acidic hydrocarbons by olefin insertion and by metal-metal exchange with other organometallics. In all cases alkyl groups are substituted by other... 

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