702701-95-9Relevant academic research and scientific papers
A convenient and selective synthesis of unsymmetrical benzoins via the cyanide ion catalyzed cleavage of benzils
Demir, Ayhan S.,Reis, ?mer
, p. 3803 - 3811 (2004)
The cyanide ion-catalyzed cleavage of benzils is used for the generation of various 'masked' acyl intermediates. The reaction of these intermediates with various aldehydes furnishes the corresponding esters of unsymmetrical benzoins in very good yields. A variety of unsymmetrical benzoin derivatives are synthesized in this way, including ferrocene derivatives. The hydrolysis of benzoin esters and their subsequent oxidation affords the corresponding unsymmetrical benzoins and benzils in high yield.
Enantioselective N-heterocyclic carbene-catalysed intermolecular crossed benzoin condensations: Improved catalyst design and the role of in situ racemisation
Delany, Eoghan G.,Connon, Stephen J.
supporting information, p. 248 - 258 (2021/01/14)
The enantioselective intermolecular crossed-benzoin condensation mediated by novel chiral N-heterocyclic carbenes derived from pyroglutamic acid has been investigated. A small library of chiral triazolium ions were synthesised. Each possessed a tertiary alcohol H-bond donor and a variable N-aryl substituent. It was found that increasing both the steric requirement and the electron-withdrawing characteristics of the N-aryl ring led to more chemoselective, efficient and enantioselective chemistry, however both quenching the reaction at different times and deuterium incorporation experiments involving the product revealed that this is complicated by product racemisation in situ (except in the case of benzoin itself), which explains the dependence of enantioselectivity on the electrophilicity of the reacting aldehydes common in the literature. Subsequent protocol optimisation, where one reacting partner was an o-substituted benzaldehyde, allowed a range of crossed-benzoins to be synthesised in moderate-good yields with moderate to excellent enantioselectivity.
Photoremovable Protecting Groups for Phosphorylation of Chiral Alcohols. Asymmetric Synthesis of Phosphotriesters of (-)-3',5'-Dimethoxybenzoin
Pirrung, Michael C.,Shuey, Steven W.
, p. 3890 - 3897 (2007/10/02)
Procedures have been developed for the preparation of dimethoxybenzoinyl (DMB) phosphate triesters that can be deprotected photochemically.These compounds can be useful in light-directed synthesis and caging.The photochemistry of a wide variety of fluorine-, oxygen-, and nitrogen-substituted benzoin acetates was examined to determine the substitution pattern in the nonacylated aromatic ring producing optimum chemical yields.Two groups, 2',3'-dimethoxybenzoin and 3',5'-dimethoxybenzoin, were found to give the highest yields of the benzofuran product and were further developed for the photochemical deprotection of phosphate esters.These reactions could not be quenched, suggesting a singlet photosolvolysis mechanism.An asymmetric synthesis of 3',5'-dimethoxybenzoin via the benzaldehyde cyanohydrin was developed that minimizes the number of diastereomers formed in the phosphorylation of chiral alcohols.A phosphoramidite reagent for the derivatization of alcohols was prepared and used to produce scalemic dimethoxybenzoinyl phosphate esters from pantolactone and glycerol, serine, and tyrosine derivatives.These compounds were deprotected photochemically to produce the phosphodiesters in high yield.
