The tyrosine \%O\%\|phosphorylation \%via\% Atherton\|Todd reaction, which was a classical reaction for phosphorylation amines, was first studied in this paper. Reaction of Boc\|Tyr\|OCH\-3, which was selected as mode...The tyrosine \%O\%\|phosphorylation \%via\% Atherton\|Todd reaction, which was a classical reaction for phosphorylation amines, was first studied in this paper. Reaction of Boc\|Tyr\|OCH\-3, which was selected as model substrate, with three dialkyl \%H\%\|phosphonate diester in the presence of CCl\-4 and triethylamine produced the corresponding tyrosine \%O\%\|phosphorylation products in a high yield(over 80%). The reaction was conducted in anhydrous THF solution and monitored by \{\}\+\{31\}P NMR and TLC. Then reaction of Boc\|Tyr\|OCH\-3 with a complicated H\|phosphonate diester, \%O\%\|3\|acetylthymidin\|5\|yl \%O\%\|isopropyl \%H\%\|phosphonate diester, also gave a good result and this would be an alternative approach for the synthesis of nucleotide \%O\%\|tyrosine (or tyrosine containing peptide) conjugate. Further, the successful \%O\%\|phosphoration of three tyrosine containing protected dipeptides, Boc\|Tyr\|Val\|OCH\-3, Boc\|Ala\|Tyr\|OCH\-3, Boc\|Tyr\|Tyr\|OCH\-3, with diisopropyl \%H\%\|phosphonate diester demonstrated the effectiveness of the method.展开更多
Till now,water based lubricants,especially aqueous solutions,have not been employed in the elastohydrodynamic lubrication(EHL)due to their poor film forming capability or low wear resistance.In this paper,we proposed ...Till now,water based lubricants,especially aqueous solutions,have not been employed in the elastohydrodynamic lubrication(EHL)due to their poor film forming capability or low wear resistance.In this paper,we proposed a method to develop water based lubricant:employing polyalkylene glycol solution as base stock to improve EHL film forming capability and using organic phosphate ester(DPZ)as anti-wear additive to improve wear resistance property.The lubricating properties of the mixed solutions,including load carrying capability,wear resistance property,friction reduction property,EHL film forming behavior,were investigated.The experimental results indicate that the mixed solution presents excellent lubricating properties,which make it a promising candidate in developing water based lubricants.展开更多
文摘The tyrosine \%O\%\|phosphorylation \%via\% Atherton\|Todd reaction, which was a classical reaction for phosphorylation amines, was first studied in this paper. Reaction of Boc\|Tyr\|OCH\-3, which was selected as model substrate, with three dialkyl \%H\%\|phosphonate diester in the presence of CCl\-4 and triethylamine produced the corresponding tyrosine \%O\%\|phosphorylation products in a high yield(over 80%). The reaction was conducted in anhydrous THF solution and monitored by \{\}\+\{31\}P NMR and TLC. Then reaction of Boc\|Tyr\|OCH\-3 with a complicated H\|phosphonate diester, \%O\%\|3\|acetylthymidin\|5\|yl \%O\%\|isopropyl \%H\%\|phosphonate diester, also gave a good result and this would be an alternative approach for the synthesis of nucleotide \%O\%\|tyrosine (or tyrosine containing peptide) conjugate. Further, the successful \%O\%\|phosphoration of three tyrosine containing protected dipeptides, Boc\|Tyr\|Val\|OCH\-3, Boc\|Ala\|Tyr\|OCH\-3, Boc\|Tyr\|Tyr\|OCH\-3, with diisopropyl \%H\%\|phosphonate diester demonstrated the effectiveness of the method.
基金supported by the National Key Basic Research Program of China(Grant No.2013CB934200)the National Natural Science Foundation of China(Grant Nos.51075227,51222507)
文摘Till now,water based lubricants,especially aqueous solutions,have not been employed in the elastohydrodynamic lubrication(EHL)due to their poor film forming capability or low wear resistance.In this paper,we proposed a method to develop water based lubricant:employing polyalkylene glycol solution as base stock to improve EHL film forming capability and using organic phosphate ester(DPZ)as anti-wear additive to improve wear resistance property.The lubricating properties of the mixed solutions,including load carrying capability,wear resistance property,friction reduction property,EHL film forming behavior,were investigated.The experimental results indicate that the mixed solution presents excellent lubricating properties,which make it a promising candidate in developing water based lubricants.
