- Biomimetic monoacylation of diols in water. Lanthanide-promoted reactions of methyl benzoyl phosphate
-
The direct monoacylation of diols by acyl phosphate monoesters in water is a biomimetic analogy to the enzymic aminoacylation of tRNA by aminoacyl adenylates. Without catalysis, acyl phosphate monoesters react rapidly with amines but very slowly with water and alcohols. Lanthanide ions dramatically and selectively facilitate the base-catalyzed monoacylation of diols in water by methyl benzoyl phosphate (MBP), a typical acyl phosphate monoester, in neutral solutions where reactive amines are protonated and unreactive. The reaction patterns and reactivity of various diols with MBP in the presence of lanthanides are consistent with a mechanism that involves internal addition from the conjugate base of the bis-bidentate complex of the lanthanide with the diol and MBP. The method is also applicable to reactions of nucleosides as evidenced by the selective monoacylation of the 2′- or 3′-hydroxyl group of adenosine, without reaction of the 5′-hydroxyl group or the 6-amino group. Analogues of adenosine without the diol are unreactive. This suggests that the method will selectively monoacylate the hydroxyl groups at the unique diol in tRNA that forms the 3′-terminus.
- Cameron, Lisa L.,Wang, Sheila C.,Kluger, Ronald
-
-
Read Online
- A green and convenient method for regioselective mono and multiple benzoylation of diols and polyols
-
An efficient method for regioselective benzoylation of diols and polyols was developed. The benzoylation is catalyzed by only 0.2 equiv of benzoate anion in acetonitrile with the addition of a stoichiometric amount of benzoic anhydride under very mild condition, leading to high yields. Compared with all other methods, this method shows particular advantage in regioselective multiple benzoylation of polyols, and in avoiding the use of any metal-based catalysts and any amine bases, which is more environment-friendly.
- Zhang, Xiaoling,Ren, Bo,Ge, Jiantao,Pei, Zhichao,Dong, Hai
-
p. 1005 - 1010
(2016/02/03)
-
- Desymmetrization of meso-glycerol derivatives induced by L -histidine-derived acylation catalysts
-
The desymmetrization of meso-glycerol derivatives bearing a 3-pyrroline-1-carbonyl (Pyroc) directing group is demonstrated through an enantioselective acylation reaction promoted by L-histidine-derived bifunctional catalysts. The desired monoacylated products are obtained in good yields (up to 74%) with high enantioselectivities (up to 99% ee). Copyright
- Sakakura, Akira,Umemura, Shuhei,Ishihara, Kazuaki
-
supporting information; experimental part
p. 1938 - 1942
(2011/10/08)
-
- Rate-acceleration in gold-nanocluster-catalyzed aerobic oxidative esterification using 1,2- and 1,3-diols and their derivatives
-
Aerobic oxidation of aldehydes to 1,2- and 1,3-diol monoesters was catalyzed by polymer-incarcerated gold nanoclusters under ambient conditions. The esterification proceeded much faster with 1,2- and 1,3-diols and their derivatives rather than with methanol. Magnum PI: Gold-nanocluster catalysts, PI-Au, that were immobilized on polystyrene-based polymers with cross-linking moieties, were used to catalyze the syntheses of 1,2 and 1,3-diol monoesters and their derivatives from aldehydes. The effect of neighboring-group participation in the esterification reaction is also described. Copyright
- Yasukawa, Tomohiro,Miyamura, Hiroyuki,Kobayashi, Shu
-
experimental part
p. 621 - 627
(2011/10/12)
-
- Regioselective opening of an oxirane system with trifluoroacetic anhydride. A general method for the synthesis of 2-monoacyl- and 1,3-symmetrical triacylglycerols
-
A trifluoroacetic anhydride-catalyzed opening of the oxirane system of glycidyl esters with a simultaneous migration of the acyl group provides a new, efficient entry to either 2-monoacylglycerols (2-MAG) or 1,3-symmetrical triglycerides (1,3-STG) as potential prodrug frameworks.
- Stamatov, Stephan D.,Stawinski, Jacek
-
p. 3659 - 3669
(2007/10/03)
-
- Ceric ammonium nitrate on silica gel for efficient and selective removal of trityl and silyl groups
-
Silicna gel-supported ceric ammonium nitrate (CAN-SiO2) was found effective for rapid and selective cleavage of trityl (Tr), monomethoxytrityl (MMTr), and dimethoxytrityl (DMTr) groups from protected nucleosides and nucleotides under mild conditions. Efficiency of deprotections depended upon the stability of th resultant carbocationic species: DMTr+ > MMTr+ > Tr+. Use of a catalytic amount of this solid-supported reagent can also efficiently and selectively remove the tert butyldimethylsilyl or the triisopropylsilyl group from a primary hydroxyl functionality in di- or trisilyl ethers of ribonucleosides. A comparative stud of deprotection reactions by utilization of CAN alone or CAN-SiO2 indicates a remarkable increase in the rate of the reactions involving a solid support. The mechanism of electron-transfer processes is proposed for the use of CAN-SiO2 in the removal of these protective groups from organic molecules.
- Hwu, Jih Ru,Jain, Moti L.,Tsai, Fu-Yuan,Tsay, Shwu-Chen,Balakumar, Arumugham,Hakimelahi, Gholam H.
-
p. 5077 - 5088
(2007/10/03)
-
- Synthesis and lipase-catalyzed enantiotope selective acetylation of 2- benzoyloxy-1,3-propanediol
-
Preparation and porcine pancreatic lipase (PPL)-catalyzed enantiotope selective acetylation of the prochiral 2-benzoyloxy-1,3-propanediol (1a) is described. The reaction with PPL and vinyl acetate gave monoacetate (2a) of 96 % e.e.
- Bódai, Viktória,Novák, Lajos,Poppe, László
-
p. 759 - 761
(2007/10/03)
-
- A Novel Method for Preparation of Glycerol Monoesters from Glycidyl Esters with Molecular Oxygen Catalyzed by Ni(II) Complex
-
In the presence of a catalytic amount of bis(3-methyl-2,4-pentanedionato)nickel(II) (Ni(mac)2), various glycidyl esters are converted into the corresponding glycerol monoester derivatives with molecular oxygen in good to high yields.
- Mukaiyama, Teruaki,Imagawa, Kiyomi,Yamada, Tohru,Takai, Toshihiro
-
p. 231 - 234
(2007/10/02)
-
- A SIMPLE ELECTROCHEMICAL OXIDATION OF ALDEHYDE ACETALS TO ESTERS IN NEUTRAL SOLUTION
-
Anodic oxidation of aldehyde acetals to esters under very mild conditions is achieved in a neutral solution by utilizing N-hydroxy-phthalimide as a mediator.The oxygen source of the oxidation is thought to be not dioxygen but water.Keywords: acetal; anodic oxidation; mediator; N-hydroxy-phthalimide; ester; glyceride.
- Masui, Masaichiro,Kawaguchi, Tetsuo,Yoshida, Sumiko,Ozaki, Shigeko
-
p. 1837 - 1839
(2007/10/02)
-