Acyl a- alkyl

A number of A/-acyl-. A/-alkyl-, and /V-arylamin on apbtbalenol sulfonic acids are used as couplers for a2o dyes. Examples of such intermediates are shown in Table 8. 

C. Amidyl Radicals from A-Acyl-A-alkyl PTOC Carbamates. 40... 

The Schmidt rearrangement of optically active a,a-bisalkylated 3-keto esters (161) regioselectively proceeds to give N-acyl a-alkylated a-amino acid esters (162) with retention of configuration and little or no racemization." Acid hydrolysis of (162), followed by treatment with propylene oxide, affords a-alkylated a-amino acids (163) in high yield and optical purity (equation 48). 

Table 6.4. A-Acyl-A -alkyl derivatives of 5-nitrofurfural hydrazone 5-0 jN Fur CH=N NRRi...

Petfluwoalkanoic anhydrides can be used as another source of fluoroalkyl substituents in the formed oxazole nucleus. For example, the reaction of A(-acyl-A(-alkyl-a-amino acids (18) or IV-acylprolines (19) with trifluoroacetic anhydride in the presence of pyridine (under Dakin-West reaction conditions) [24] affords 5-trifluoromethyloxazoles (20 or 21) in good yields [25,26] (best yields are observed for R =Bn). 

Grieco et al. have also reported the use of C-acyl iminium ions as heterodienophiles in the aqueous Diels-Alder reaction with cyclopentadiene [8]. This work details the cyclocondensation of C-acyl A-alkyl iminium ions 18 and C-acyl A-unsubstituted iminium ions 19 with cyclopentadiene in water ... 

Phenyl isocyanide (PhNC) has been utilized in the U-4CR to synthesize pentasubstituted pyrroles [50]. The U-4CR product 111 was converted to the corresponding Ai-acyl-A-alkyl-a-amino acid 112 with the treatment with B0C2O -dimethylaminopyridine (DMAP) in tetrahydrofuran (THF) followed by 1 N LiOH... 

It should be noted that the Friedel-Crafts acylation differs from the Friedel-Crafts alkylation (compare Sections IV,3-4 and discussion preceding Section IV,1) in one important respect. The alkylation requires catal3d.ic quantities of aluminium chloride, but for acylation a molecular equivalent of aluminium chloride is necessary for each carbonyl group present in the acylating agent. This is because aluminium chloride is capable of forming rather stable complexes with the carbonyl group these complexes probably possess an oxonium... 

Neither Friedel-Crafts acylation nor alkylation reactions can be earned out on mtroben zene The presence of a strongly deactivating substituent such as a nitro group on an aromatic ring so depresses its reactivity that Friedel-Crafts reactions do not take place Nitrobenzene is so unreactive that it is sometimes used as a solvent m Friedel-Crafts reactions The practical limit for Friedel-Crafts alkylation and acylation reactions is effectively a monohalobenzene An aromatic ring more deactivated than a mono halobenzene cannot be alkylated or acylated under Friedel-Crafts conditions... 

When aiomatics aie present, they can capture the intermediate vinyl cation to give P-aryl-a,P-unsatutated ketones (182). Thus acylation of alkyl or aryl acetylenes with acyhum salts in the presence of aromatics gives a,P-unsaturated ketones with a trisubstituted double bond. The mild reaction conditions employed do not cause direct acylation of aromatics. 

Alkoxyall l Hydroperoxides. These compounds (1, X = OR , R = H) have been prepared by the ozonization of certain unsaturated compounds in alcohol solvents (10,125,126). 2-Methoxy-2-hydroperoxypropane [10027-74 ] (1, X = OR , R" = methyl), has been generated in methanol solution and spectral data obtained (127). A rapid exothermic decomposition upon concentration of this peroxide in a methylene chloride—methanol solution at 0°C has been reported (128). 2-Bromo-l-methoxy-l-methylethylhydroperoxide [98821-14-8]has been distilled (bp 60°C (bath temp.), 0.013 kPa) (129). Two cycHc alkoxyaLkyl hydroperoxides from cyclodecanone have been reported (1, where X = OR R, R = 5-oxo-l, 9-nonanediyl) with mp 94—95°C (R" = methyl) and mp 66—68°C (R" = ethyl) (130). Like other hydroperoxides, alkoxyaLkyl hydroperoxides can be acylated or alkylated (130,131). 

Acyl O-alkyl monopeioxycaibonates (22) aie obtained from the reaction of alkyl chloroformates with peroxycarboxyhc acids in the presence of a base (44,212) ... 

Uses. The largest usage of PCl is to produce phosphonic acid, H PO, which in reaction with iminodiacetic acid and formaldehyde forms a glyphosate intermediate that is decarboxymethylated to glyphosate, an effective nonselective herbicide (see Herbicides). Phosphoms trichloride is also a convenient chlorinating reagent for producing various acyl and alkyl chlorides. 

Important analogs of aniline include the toluidines, xyUdines, anisidines, phenetidines, and its chloro-, nitro-. A/-acetyl. A/-alkyl. A/-aryl. A/-acyl, and sulfonic acid derivatives. 

Diarylamines can be A/-alkylated with anhydrides and acyl haUdes or A/-alkylated with alkyl haUdes, alkyl sulfates, and tri- / -alkylphosphites. Diphenylamine derivatives of alkyl—aryl gaUium, germanium, phosphoms, and siUcon are known (17), eg, pentaphenylgermanamine [64653-46-9]. 

Acyl-pyrroles, -furans and -thiophenes in general have a similar pattern of reactivity to benzenoid ketones. Acyl groups in 2,5-disubstituted derivatives are sometimes displaced during the course of electrophilic substitution reactions. iV-Alkyl-2-acylpyrroles are converted by strong anhydrous acid to A-alkyl-3-acylpyrroles. Similar treatment of N-unsubstituted 2- or 3-acyIpyrroles yields an equilibrium mixture of 2- and 3-acylpyrroles pyrrolecarbaldehydes also afford isomeric mixtures 81JOC839). The probable mechanism of these rearrangements is shown in Scheme 65. A similar mechanism has been proposed for the isomerization of acetylindoles. 

In the diaziridine field many compounds are known bearing N-YL, A/-alkyl and A-acyl groups, but here no dramatic changes in reactivity are caused by A-substituents. N-Aryldiaziridines are underrepresented. The ring carbon is in the oxidation state of a carbonyl compound or, in the diaziridinones (5) and the diaziridinimines (6) that of carbonic acid. In single cases, diaziridine carbon bears chlorine or fluorine. 

During electrochemical fluorination retention of important functional groups or atoms in molecules is essential. Acyl fluorides and chlorides, but not carboxylic acids and anhydrides (which decarboxylate), survive perfluorination to the perfluorinated acid fluorides, albeit with some cyclization in longer chain (>C4) species [73]. Electrochemical fluorination of acetyl fluoride produces perfluoro-acetyl fluoride in 36-45% yields [85]. Electrochemical fluorination of octanoyl chloride results in perfluorinated cyclic ethers as well as perfluorinated octanoyl fluonde. Cyclization decreases as initial substrate concentration increases and has been linked to hydrogen-bonded onium polycations [73]. Cyclization is a common phenomenon involving longer (>C4) and branched chains. a-Alkyl-substituted carboxylic acid chlorides, fluorides, and methyl esters produce both the perfluorinated cyclic five- and six-membered ring ethers as well as the perfluorinated acid... 

Correlations with o in carboxylic acid derivative reactions have been most successful for variations in the acyl portion, R in RCOX. Variation in the alkyl portion of esters, R in RCOOR, has not led to many good correlations, although use of relative rates of alkaline and acidic reactions, as in the defining relation, can generate linear correlations. The failure to achieve satisfactory correlations with cr for such substrates may be a consequence of the different steric effects of substituents in the acyl and alkyl locations. It has been shown that solvolysis rates of some acetates are related to the pA", of the leaving group, that is, of the parent alcohol. The pK of alcohols has been correlated with but this relationship... 

Those derivatives that result by the action of acylating and alkylating reagents, such as A -acetylcotarnine (9b), A-benzoylcotarnine (9c), or cotarnmethin methyliodide (19) can only be derived from... 

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