Carboxylic esters with

Table 3. Reaction of C2H502C(CF2)20(CF2)2MgBr with Carboxylic Esters, RCO2C2H5 ...

TABLE 25. Reaction of dimsyl anion with carboxylic esters... 

Although more studies have been devoted to the mechanism of the acylation of amines with carboxylic esters than with other reagents, the mechanistic details are not yet entirely clear.In its broad outlines, the mechanism appears to be essentially Bac2. ° Under the normal basic conditions, the reaction is general base... 

Coupling of Organometallic Reagents With Carboxylic Esters... 

For a list of preparations of ketones by the reaction of organometallic compounds with carboxylic esters, salts, anhydyrides, or amides, with references, see Ref. 568, pp. 685, 693. 

When the same reaction is carried out with carboxylic esters R COOR", a-diketones RCOCOR are obtained. ... 

Acylation of oc-sulphinyl carbanions. Synthesis of fS-oxosulphoxides. oi-Ketosulphoxides have found very broad application in organic synthesis (see, for example. Reference 532). For this reason, a great deal of examples of their syntheses appear in the chemical literature. The main approach to this class of functionalized sulphoxides involves the reaction of a-sulphinyl carbanions with carboxylic esters or acyl halides. 

The treatment of 2-fluorophenyl-2-iodophenyl ethers, amines, and thioethers with 3.3 equivalents of f-BuLi and further reaction with selected electrophiles gave rise to functionalized carbazoles, dibenzofurans, and dibenzothiophenes in a direct and regioselective manner. A selected example is illustrated below <06JOC6291>. Benzyl 2-halophenyl ethers was treated with f-BuLi, and then reacted with carboxylic esters to give 2,3-disubstituted benzo[t>]furans <06JOC4024>. 

Bis(tribuyltin) oxide reacts with carboxylic esters in ether at room temperature to give the corresponding tributyltin carboxylate and tributyltin alkoxide, and this reaction is recommended for removing protecting ester groups in the presence of other functional substituents.358-360... 

Although solutions of molybdenum complexes A in methylcyclohexane or benzene are stable for several weeks at room temperature [416], these complexes are sensitive towards oxygen and protic solvents [813,814]. Aldehydes are quickly olefinated by complexes A, whereas variable reactivity is observed towards ketones [416,736]. With carboxylic esters usually no reaction occurs. 

With carboxylic esters, two types of MeLafferty rearrangements may be observed and ions resulting from either fragmentation pathway are observed in the mass spectrum ... 

Coupling of Organometallic Reagents with Carboxylic Esters Alkyl-de-acyloxy-substitution... 

When the same reaction is carried out with carboxylic esters R COOR", ot-diketones RCOCOR are obtained.410 Another way to add RCO to aldehydes and ketones is to treat the substrate with ArCOLi, generated by treating ArCOTeBu with BuLi.411... 

Since in numerous cases of hydrolysis of nitric esters the presence of a large amount of nitrate ion has been established, which could be liberated only by rupture of the C—0 bond, the factors that influence the direction of this process should be discussed. Several investigations have thrown light on this problem, which is more complicated than with carboxylic esters, since during the hydrolysis of the latter compounds whether in acid or in alkaline medium only rupture of the ester bond can take place. This has been established in various ways including the use of water containing an 180-isotope. In general the hydrolysis of carboxylic esters can be defined by the equation ... 

The same intermediate was also formed by direct deprotonation of N,N-dimethylthioformamide with LDA, and was used to prepare a-oxo thioami-des by acylation with carboxylic esters [141]. Deprotonation of the formed thioamides laterally takes place on the AT-methyl group and intramolecular addition of the anion to the carbonyl group provides a new entry to /1-thio-lactam rings. 

Bis(2-lithioallyl)amines 297, a class of non-conjugated dilithio reagents which were formed from 296, were reported by Barluenga and coworkers to react with carboxylic esters affording cyclic alcohols 299 after hydrolysis (Scheme 91)169. A dilithiated dihydropyrrol 298 was generated from 297 via intramolecular carbolithiation of a lithiated double bond and served as the key intermediate. 

More recently, we have also described a new and unexpected reactivity of these 1,4-dianions 321 with carboxylic esters. Depending on the reaction conditions it is possible to obtain selectively /9, y-unsaturated ketones 324 or bicyclic cyclopentenol derivatives 325 (Scheme 83). In this work we have also shown additional evidence that support the car-bolithiation reaction pathway for these transformations. Thus, iV,iV-bis(2-lithioallyl)amines... 

Only monoacylated products 93 are isolated when 1-benzyl- and l-phenyl-2-methyli-midazolines (92) are reacted with carboxylate esters under the reaction conditions illustrated in equation 3210,104. 

A mild and efficient deprotection of phosphate triesters involves nucleophilic attack by weakly basic nucleophiles such as iodide, thiolate and amines at the O-C bond with synchronous expulsion of a phosphate diester as the leaving group [Scheme 7.6]. The reaction is especially useful for the deprotection of methyl, benzyl and allyl phosphates as in Scheme 7.8 shown below. An analogous reaction occurs with carboxylic esters but the conditions required are more stringent because the carboxylate anion is a poorer leaving group (see section 6.3.1),... 

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