Acylation with carboxylic acid ester

Acylation with carboxylic acid esters N-Acylation of j5-ketocarboxylic acid amides C-Acylation of diacylamines... 

These reactions were demonstrated with pure enzymes or various biological media such as human peripheral blood mononuclear cells uninfected or infected with HIV. In the latter case, highly promising antiviral results were obtained. Furthermore, a variety of amino acyl residues, carboxylic acid ester moieties, and aryl substituents X have been reported. 

Acylation of a-lithio-a-phosphonylalkyl sulfides (440) with carboxylic acid esters was utilized as a facile route to a-alkylsulfenyl substituted p-ketophos-phonates (441). Keto-enol tautomerism of these new compounds in different solvents as well as regiochemistry of alkylation and acylation reactions and usefulness for HWE olefination reactions were studied (Scheme 104). ... 

In general, salt-free solutions of ylides do not react with methyl or ethyl esters of carboxylic acids. Better results can be obtained when activated esters (e.g. phenyl or pyridyl esters) are used for acyl-ation. " Acylation with carboxylic acid anhydrides also requires only one mole of starting ylide (equation 73). ... 

Chiral 2-thiazolidinethiones, e.g., 40, prepared from cysteine esters by the reaction with carbon disulfide23, are used for the enantiotopic differentiation of methylene groups (Section C.). Similarly, carbon disulfide reacts with amino alcohols such as (5)-2-amino-J-butanol or (S)-2-amino-3-methyl-1-butanol (valinol) to give the 2-thiazolidinethiones (S)-ETT 42 and (S)-IPTT 4124 which have been used as auxiliaries (after Y-acylation with carboxylic acids and dicyclo-hexylcarbodiimide) in acylimonium ion cyclizations (Section D.I.4.5.). 

Carboxylic acid hydiazides are prepared from aqueous hydrazine and tfie carboxylic acid, ester, amide, anhydride, or halide. The reaction usually goes poody with the free acid. Esters are generally satisfactory. Acyl halides are particularly reactive, even at room temperature, and form the diacyl derivatives (22), which easily undergo thermal dehydration to 1,3,4-oxadiazoles (23). Diesters give dihydtazides (24) and polyesters such as polyacrylates yield a polyhydrazide (25). The chemistry of carboxyhc hydrazides has been reviewed (83,84). 

An interesting class ot covalent Inflates are vin l and ar>/ or heteroaryl Inflates Vinyl inflates are used for the direct solvolytic generation of vinyl cations and for the generation of unsaturated carbenes via the a-elimination process [66] A triflate ester of 2-hydroxypyridine can be used as a catalyst for the acylation of aromatic compounds with carboxylic acids [109] (equation 55)... 

Esterification with carboxylic acid anhydrides (Section 15.8) Carboxylic acid anhydrides react with alcohols to form esters in the same way that acyl chlorides do. 

In the previous review (91YGK205, 99H1157), we reported that l-hydroxy-4-nitroindole forms active ester derivatives by reaction with carboxylic acids, which can be applied to acylation of various nucleophiles. To expand the scope of the reaction and obtain novel fungicidal compounds, an attempt has been made to prepare derivatives of wasabi phytoalexin 109 (98P1959). 

In the course of this study, the authors determined /Lvalues for dibenzyl, methyl phenyl, methyl p-nitrophenyl, di-p-tolyl, di-isopropyl and tetramethylene sulphoxides and for diethyl, dipropyl and dibutyl sulphites. The /Lscales are applied to the various reactions or the spectral measurements. The /Lscales have been divided into either family-dependent (FD) types, which means two or more compounds can share the same /Lscale, family-independent (FI) types. Consequently, a variety of /Lscales are now available for various families of the bases, including 29 aldehydes and ketones, 17 carboxylic amides and ureas, 14 carboxylic acids esters, 4 acyl halides, 5 nitriles, 10 ethers, 16 phosphine oxides, 12 sulphinyl compounds, 15 pyridines and pyrimidines, 16 sp3 hybridized amines and 10 alcohols. The enthalpies of formation of the hydrogen bond of 4-fluorophenol with both sulphoxides and phosphine oxides and related derivatives fit the empirical equation 18, where the standard deviation is y = 0.983. Several averaged scales are shown in Table 1588. 

Triple bonds can give enol esters or acylals when treated with carboxylic acids. Mercuric salts are usually catalysts, and vinylic mercury compounds... 

Similar additions have been successfully carried out with carboxylic acids, anhydrides, acyl halides, carboxylic esters, nitriles, and other types of compounds. These reactions are not successful when the alkene contains electron-withdrawing groups such as halo or carbonyl groups. A free-radical initiator is required, usually peroxides or UV light. The mechanism is illustrated for aldehydes but is similar for the other compounds ... 

Much more important than these reactions, however, are the reactions of CDI and its analogues with carboxylic acids, leading to AAacylazoles, from which (by acyl transfer) esters, amides, peptides, hydrazides, hydroxamic acids, as well as anhydrides and various C-acylation products may be obtained. The potential of these and other reactions will be shown in the following chapters. In most of these reactions it is not necessary to isolate the intermediate AAacylazoles. Instead, in the normal procedure the appropriate nucleophile reactant (an alcohol in the ester synthesis, or an amino acid in the peptide synthesis) is added to a solution of an AAacylimidazole, formed by reaction of a carboxylic acid with CDI. Thus, CDI and its analogues offer an especially convenient vehicle for activation of... 

As with carboxylic acids obtained by palladium hydroxycarbonylation, their derivatives esters, amides, anhydrides and acyl halides are synthesized from alkenes, CO and HX (X = OR, NR2 etc.). The Pd-catalyzed methoxycarbonylation is one of the most studied reactions among this type of catalyzed carbonylations and has been reviewed and included in reports of homogeneous catalysis.625, 26 The methoxycarbonylation has been applied to many different substrates to obtain intermediates in organic syntheses as well as specific products. For instance, the reaction has been applied for methoxycarbonylation of alkynes666 Highly efficient homogeneous Pd cationic catalysts have been reported and the methoxycarbonylation of alkynes has been used to develop economically attractive and environmentally benign process for the production of methyl... 

As in Section 5.06.9.1, the assignments are sometimes arbitrary. Important routes to oxadiazoles, aminooxadiazoles, oxadiazolinones, and oxadiazolinethiones involving the reaction of hydrazides RCONHNH2 with carboxylic acids, acyl chlorides, alkyl esters, or trialkyl orthoesters are described in Section 5.06.9.2.1, reactions with carbon disulfide... 

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