Benzyl carboxylates

A similar steric effect was observed in the reaction of benzyl carboxylate (44). When 44a-d were treated with Bu OK under solvent-free conditions at around 100 °C for 30 min, the corresponding condensation products 45a (75%), 45b (66%), 45c (64%), and 45d (84%) were obtained in the yields indicated [9] (Scheme 6). When the same reactions of 44a-d and Bu OH were carried out in toluene under reflux for 16 h, no condensation product was obtained and 44a-d were recovered unchanged. In solution reactions, exchange of the alkoxy group occurs among the substrate, reagent, and solvent. Therefore, the alkoxy groups of the ester, metal alkoxide, and alcohol used as a solvent should be identical. 

Benzyldimethyldodecylammonium hydroxide (BDDOH), in emulsion polymerization of siloxanes, 22 561 Benzyl formate, physical properties, 6 292t Benzylic carboxylic esters, cleavage of,... 

Common esters such as alkyl and benzyl carboxylates are easily dealkylated by sodium hydrogen telluride, sodium telluride and sodium ditelluride in DMF. In accordance with a typical S 2 displacement at the aUcoxy group carbon, methyl, ethyl and benzyl esters react smoothly. The nucleophilicity of the reagents is enhanced by the polar aprotic solvent, and the reactivity decreases with higher alkoxy chains due to steric hindrance (e.g. 

Nonenolizable benzylic carboxylates, such as pivalates 55, were lithiated in the presence of a catalytic amount of naphthalene (10%) and the electrophile, to yield, after hydrolysis, the expected products 20. The application of the same reaction to different ally lie or benzylic carbonates 56 yielded the same type of products 20 (Scheme 18) °. 

The first general iron-catalyzed arylation of benzyl alcohols and benzyl carboxylates was published by our group in 2005 [56]. A practical synthesis of a multitude of... 

The research group of Muzart and Henin studied extensively the palladium-catalyzed EDP of allyl- or benzyl-carboxylated compounds. Mainly two types of substrates, prochiral enol carbonates A and racemic (3-keto esters B, were used to afford enols C as transient species [25]. In the presence of a chiral proton source, asymmetric protonation/tautomerization of enols led to enantioenriched ketones D... 

The anodic oxidation of carboxylic acids has also been carried out using a solid-supported base in methanol. Non-Kolbe-type electrolysis takes place to give the corresponding methoxylated product (Equation 12.7). The acid-base reaction between a carboxylic acid and a solid-supported base seems to reduce the cell voltage and makes the electrochemical reaction possible. Kolbe-type carbon-carbon coupling using aliphatic and benzylic carboxylic acids has also been accomplished using this method [26]. Based on a similar concept, anodic fluorination by an alkali metal... 

Addition to styrenes. r-Butyllithium (other alkyllithiums also) adds to the terminus of styrenes. Benzylic carboxylation is feasible.When the substrates contain an allyloxy or benzyloxy group the allyl or benzyl residue is transfer to the benzylic position. ... 

Contrary to aryl carobxylates, benzyl carboxylates generally undergo type a scission. However, the pyridinomethyl esters also effectively guide the bond cleavage of type b probably via intramolecular coordination (Scheme 3.35) [67]. Since decarbonylation from the resulting acyl group rapidly occurs in this system, catalytic decarboxylation takes place in the presence of ammonium formate as a hydride source. 

Examination of the structure of this ligand in detail reveals how it is ideal for its purpose (Fig. 17). Two vacant adjacent coordination positions are required cyclen was chosen because it has long been known that that ligand can only bind to cobalt(III) in a folded tetradentate manner, thereby leaving two vacant coordination positions. The donor atoms of the pendant carboxyl group must not be capable of reaching the metal ion, but they must be able to interact with a bound carboxylate derivative the meta-benzyl carboxylic acid group provides such an orientation. Further, this choice of structural moiety opens the way for facile synthesis of the desired product. 

Lithium N-tert-butyl-N-cyclohexylamide Stcreospedfic benzylic carboxylation 602. H... 

Although the preparation of benzyl carboxylate esters from benzyl bromide and carboxylate anions is not the most common route to these compounds, the reaction is possible when carried out in DMF or using zinc carboxylates. ... 

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