Carboxylic esters, aryl compounds

Phenolic compounds are weaker nucleophiles and better leaving groups than aliphatic alcohols. They do not yield polyesters when reacted with carboxylic acids or alkyl carboxy lates. The synthesis of polyesters from diphenols is, therefore, generally carried out through the high-temperature carboxylic acid-aryl acetate or phenyl ester-phenol interchange reactions with efficient removal of reaction by-product (Schemes 2.10 and 2.11, respectively). 

Organomercury compounds undergo a similar reaction. Alkyl and aryl Grignard reagents can be converted to carboxylic esters with Fe(CO)5 instead of CO. Amides have been prepared by the treatment of trialkyl or triarylboranes with CO and an imine, in the presence of catalytic amounts of cobalt carbonyl ... 

Coupling of Organometallic Compounds with Aryl Halides, Ethers, and Carboxylic Esters... 

Hydroxycarbonylation and alkoxycarbonylation of alkenes catalyzed by metal catalyst have been studied for the synthesis of acids, esters, and related derivatives. Palladium systems in particular have been popular and their use in hydroxycarbonylation and alkoxycarbonylation reactions has been reviewed.625,626 The catalysts were mainly designed for the carbonylation of alkenes in the presence of alcohols in order to prepare carboxylic esters, but they also work well for synthesizing carboxylic acids or anhydrides.137 627 They have also been used as catalysts in many other carbonyl-based processes that are of interest to industry. The hydroxycarbonylation of butadiene, the dicarboxylation of alkenes, the carbonylation of alkenes, the carbonylation of benzyl- and aryl-halide compounds, and oxidative carbonylations have been reviewed.6 8 The Pd-catalyzed hydroxycarbonylation of alkenes has attracted considerable interest in recent years as a way of obtaining carboxylic acids. In general, in acidic media, palladium salts in the presence of mono- or bidentate phosphines afford a mixture of linear and branched acids (see Scheme 9). 

Amino-substituted naphthoquinones and heterocyclic variants have been disclosed in the patent literature as 5-LO inhibitors. Compounds represented by (80) (X = C, N) from Lilly inhibited SRS-A release from sensitized guinea-pig lung tissue [218]. Similar compounds such as (81) (R = carboxylic ester, acyl, or aryl) and related naphthalene derivatives, from American Cyanamid, gave good inhibition in guinea-pig ISN (at 10 //g/ml) and in passive cutaneous anaphylaxis in mice (25-60 /zM i.p.) [219,220]. 

Apart from aryl esters and amides of carboxylic acids, aryl carbonates, and carbamates, other types of organic compound have been reported to undergo PFR. They include oxalates, formiates, sulfonates, sulfonamides, thioesters, selenoesters, and telluroesters. 

Vinylic and aryl halides can be used to vinylate or arylate carboxylic esters (but not ketones) by the use of NiBr2 as a catalyst.1463 However, ketones have been vinylated by treating their enol acetates with vinylic bromides in the presence of a Pd compound catalyst.1464 Also as in 0-94, this reaction can be used to close rings.1465 In one example of this, rings have been closed by treating a diion of a dialkyl succinate with a l,cu-dihalide or ditosylate,1466, e.g. ... 

Organomercury compounds undergo a similar reaction.388 Alkyl and aryl Grignard reagents can be converted to carboxylic esters with Fe(CO)s instead of CO.389... 

Photolysis of oc-oxo carboxylic esters takes an unusual course 73 in contrast to the result of heterolytic decarbonylation, this type of compound yields, alongside carbon monoxide, a ketone and an aldehyde, and not the carboxylic ester containing one fewer carbon atoms the reaction can be generalized as follows, where R = alkyl or aryl and R and R" = alkyl and/or H ... 

In addition to direct formation from an arylhydrazine and a carbonyl compound, iV-aryl-hydrazones can be prepared from aryldiazonium ions by coupling with enolates or enamines (Japp-Klingemann reaction). This reaction has most frequently been applied to j -ketoesters. The coupling product undergoes deacylation so that the ultimate product of Fischer cycUzation is an indole-2-carboxylate ester (Scheme 58) <92JMC4823>. 

A large number of new tropanyl esters and other related compounds have been prepared, with the purpose of contributing further structure-pharmacological activity relationships. Inter alia, para-substituted tropanyl benzoates (for studies of the substrate specificity of atropine esterase), benzazocines (narcotic antagonists) from 6-hydroxytropinone, 5-aryl-furan-2-carboxylic esters of pseudotropine (local anaesthetics), 2,4,5-trimethylpyrrole-3-carboxylic acid... 

DiphenylketeneJtriethylamine Carboxylic acid aryl esters from carboxylic acids via mixed carboxylic acid anhydrides Optically active compounds... 

PDHc El, phosphonate structural unit as moiety A was linked with an aryl or a heterocycle group as moiety B by a carboxylate ester bond to form 1-oxophos-phonic acid derivatives (Scheme 1.18). In order to find a lead compound with desired herbicidal activity, different structural unit Q was introduced into this phosphonate scaffold resulting a series of 1-oxophosphonic acid derivatives [68]. 

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