Peptide bond formation has drawn more and more attention due to its importance in medicinal chemistry and drug discovery.Using active esters to construct peptide bonds is an indispensable strategy in this field.We her...Peptide bond formation has drawn more and more attention due to its importance in medicinal chemistry and drug discovery.Using active esters to construct peptide bonds is an indispensable strategy in this field.We herein report a fast and efficient amination reaction to synthesize peptides from catechol diesters.Catechol monoesters are good active esters in peptide synthesis due to the anchimeric assistance effect.In previously reported work,the amination reaction was inactivated if the 2-hydroxyl group in the catechol esters was functionalized.However,we found an unusual acceleration of the amination reactivity when the 2-hydroxyl group was functionalized as an ester group.The reaction can be complete in 2−3 min in some cases.This acceleration was found through experimental studies to not result from the anchimeric assistance effect.We proposed aπ*−π*interaction pathway between the two proximal ester groups.Some computational studies were made to support this assumption.展开更多
Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） me...Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） method at the B3LYP/6-31G＊ level. Based on the quantum-chemical calculation results and the Pearson coefficients between FA and quantum- chemical parameters, V, LogP, MR and EHOMO are shown to be the important relative factors which affect FA of the title compounds.展开更多
The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation perform...The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.展开更多
Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their cry...Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their crystal structures were determined by single-crystal X-ray diffraction method. The steric hindrances posed by tert-butyl groups play an important part in the synthesis and the self-assembly of the two compounds. Compound 6 was synthesized from the corresponding ester, which was obtained by the reaction of acid chloride with ammonia. In the crystal structure, compound 4 presents a highly symmetric molecular structure, while for compound 6, because of absence of tert-butyl groups, it presents a more flexible molecular structure.展开更多
基金supported by Grant-in-Aid for Scientific Research from the New Energy and Industrial Technology Development Organization(NEDO)project(JPNP14004)and The Naito Foundation.
文摘Peptide bond formation has drawn more and more attention due to its importance in medicinal chemistry and drug discovery.Using active esters to construct peptide bonds is an indispensable strategy in this field.We herein report a fast and efficient amination reaction to synthesize peptides from catechol diesters.Catechol monoesters are good active esters in peptide synthesis due to the anchimeric assistance effect.In previously reported work,the amination reaction was inactivated if the 2-hydroxyl group in the catechol esters was functionalized.However,we found an unusual acceleration of the amination reactivity when the 2-hydroxyl group was functionalized as an ester group.The reaction can be complete in 2−3 min in some cases.This acceleration was found through experimental studies to not result from the anchimeric assistance effect.We proposed aπ*−π*interaction pathway between the two proximal ester groups.Some computational studies were made to support this assumption.
基金talents in University (NCET-04-0649) the Natural Science Foundation of Shandong Province (Y2006B07,Z2006B01)
文摘Nine novel triazole compounds containing ester group were designed and synthesized. Their structures were confirmed by elemental, ^1H NMR and IR analyses, and optimized by means of DFF （Density Functional Theory） method at the B3LYP/6-31G＊ level. Based on the quantum-chemical calculation results and the Pearson coefficients between FA and quantum- chemical parameters, V, LogP, MR and EHOMO are shown to be the important relative factors which affect FA of the title compounds.
基金supported by the Natural Science Foundation of Guizhou Province(QKJ[2014]2140 and QJTD[2012]052)
文摘The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.
基金Supported by the National Natural Science Foundation of China(20772092)the Hubei Province Natural Science Fund for Distinguished Young Scholars(2007ABB021)
文摘Two 1,3-alternate thiacalix[4]arene derivatives bearing amide groups, 1,3-alternate p-tert-butylthiacalix[4]arene tetraamide （4）, and 1,3-alternate p-H-thiacalix[4]arene tetraamide （6） were prepared, and their crystal structures were determined by single-crystal X-ray diffraction method. The steric hindrances posed by tert-butyl groups play an important part in the synthesis and the self-assembly of the two compounds. Compound 6 was synthesized from the corresponding ester, which was obtained by the reaction of acid chloride with ammonia. In the crystal structure, compound 4 presents a highly symmetric molecular structure, while for compound 6, because of absence of tert-butyl groups, it presents a more flexible molecular structure.
