34904-93-3Relevant academic research and scientific papers
Asymmetric transfer hydrogenation of unsymmetrical benzils
Zhang, Hao,Feng, Dandan,Sheng, Haibo,Ma, Xuebing,Wan, Jinwei,Tang, Qian
, p. 6417 - 6423 (2014/02/14)
In this paper, the asymmetric transfer hydrogenation of unsymmetrical benzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40°C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetrical benzils with the o-substituents such as electron-donating (R = CH3, OCH3) and electron-withdrawing groups (R = F, Cl, CF3) resulted in poor yields (0% to 31.2%), even at 40°C for 72 h. These products had inefficient diastereoselectivities (syn/anti = 1.5 to 5.0/1) caused by steric effects. Furthermore, the results of a dynamic-kinetic study were used to propose a plausible reaction pathway of unsymmetrical benzil using 3-methoxy-1,2-diphenyl ethanedione as an example.
Biomolecular labeling
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Sheet 72, (2010/01/31)
A method for using an organic compound to label polynucleotides is described. The method utilizes an organic compound including an oligonucleotide, and electrophilic active site, an active complex, and a phosphate binding site. The oligonucleotide has a sequence that is complimentary to a specific region of a polynucleotide. This facilitates labeling of DNA or RNA at a specific site in its sequence. The active site consists of a stable precursor, and only becomes reactive upon activation. Leaving and protecting functional groups may be attached to the active site in order to facilitate the formation of a stable precursor and subsequent activation. The active complex may be a drug, polypeptide or a reporter molecule such as an isotope or fluorescing compound. The phosphate binding sites may be any functional group capable of forming ionic bonds with phosphate oxygens. Nucleotide labeling using this compound does not interfere with a polynucleotide sequence. The described method for utilizing this compound may be performed in situ. Latent reactivity is utilized to make the reaction chemically specific, alkylating only phosphodiester groups on the polynucleotide. A lactonization reaction traps the trialkylphosphate in a stable form.
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.
Reductive Coupling of Benzoyl Cyanide and Carbonyl Compounds by Aqueous Ti(III) Ions. A New Convenient and Selective Access to the Less Stable Mixed Benzoins
Clerici, Angelo,Porta, Ombretta
, p. 2889 - 2893 (2007/10/02)
The reactive species formed by the Ti(III) ion reduction of benzoyl cyanide (1) adds to the C-atom of carbonyl compounds 2 under simple experimental conditions.The intermediate 1,2-diols 3 are smoothly converted, without isolation, into the less thermodynamically stable mixed benzoins 4, which are not accessible by the classical benzoin condensation.The possible mechanisms involved in the reaction are discussed.
Application of Cyanophosphates in Organic Synthesis. Reactivity of α-Cyano-α-diethylphosphonooxy Anions
Kurihara, Takushi,Santo, Kazunori,Harusawa, Shinya,Yoneda, Ryuji
, p. 4777 - 4788 (2007/10/02)
The utility of the cyanohydrin diethylphosphates derived from aldehydes (arylaldehydes,crotonaldehyde, and cinnamaldehyde) as an acyl anion equivalent was examined.Deprotonation of cyanophosphates with n-butyllithium in the presence of tetramethylethylene
