Tetrahydrofolate (THF) coenzymes are involved in biochemical transfer of aone-carbon fragment at different oxidation levels. The study of THF models may providea valuable class of reagents for group transfer reactions...Tetrahydrofolate (THF) coenzymes are involved in biochemical transfer of aone-carbon fragment at different oxidation levels. The study of THF models may providea valuable class of reagents for group transfer reactions with practical significance. Onlya few researches about 5, 10-methenyl-THF models have been reported in literature.展开更多
Four 1, 2, 3-trisubstituted imidazolinium iodides which were used as 5,10-^+CPh-THF model (7-10) at formic acid oxidation level were synthesized. The benzylidyne group (phenyl- substituted one carbon unit)transfer rea...Four 1, 2, 3-trisubstituted imidazolinium iodides which were used as 5,10-^+CPh-THF model (7-10) at formic acid oxidation level were synthesized. The benzylidyne group (phenyl- substituted one carbon unit)transfer reactions from these compounds to Grignard reagent were in- vestigated, and the reactions of these compounds with KBH_4 and NaOH were also studied.展开更多
Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr+Cl04- or PhAcr+Cl04- as photocatalysts under visible light irradiation at room temperature.
The addition-hydrolysis reaction of benzimidazolium salt with some mono- and bifunctional amine nucleophiles is reported, and a novel method of biomimetic synthesis for formamides and heterocycle compounds is provided.
An efficient method for the selective hydrogenation of a series of α,β-epoxyketones to β-hydroxyketones using catalytic amount of two sulfinyl analogues of NAD^+ model compounds is reported. The lack of any diaste...An efficient method for the selective hydrogenation of a series of α,β-epoxyketones to β-hydroxyketones using catalytic amount of two sulfinyl analogues of NAD^+ model compounds is reported. The lack of any diastereoselectivity for the formation of β-hydroxyketones with optically pure sulfinyl analogue of NAD^+ model supports the radical mechanism proposed previously.展开更多
Heterolytic and homolytic C D bond dissociation energies of three NADH models: BNAH-4,4-d 2 , HEH-4,4-d 2 and AcrD 2 in acetonitrile were first estimated by using an efficient method. The results showed that the heter...Heterolytic and homolytic C D bond dissociation energies of three NADH models: BNAH-4,4-d 2 , HEH-4,4-d 2 and AcrD 2 in acetonitrile were first estimated by using an efficient method. The results showed that the heterolytic C D bond dissociation energies are 65.2, 70.2, and 81.9 kcal/mol and the homolytic C D bond dissociation energies are 72.66, 70.69, and 74.95 kcal/mol for BNAH-4,4-d 2 , HEH-4,4-d 2 , and AcrD 2 , respectively. According to the bond dissociation energy differences of isotope isomers, an interesting conclusion can be made that the primary kinetic isotope effects are dependent not only on the zero-point energy difference of the isotope isomers, but also on the types of C D bond dissociations, and the C D bond homolytic dissociations should have much larger primary kinetic isotope effects (26.9 28.8) than the corresponding C D bond heterolytic dissociations (3.9-5.4).展开更多
Since the early studies of Mannich, Mannich reaction has become an important tool for the synthesis of new compounds. Mannich bases can be either directly employed or used as intermediates. In this work, the one-carbo...Since the early studies of Mannich, Mannich reaction has become an important tool for the synthesis of new compounds. Mannich bases can be either directly employed or used as intermediates. In this work, the one-carbon unit transfer reaction of tetrahydrofolate coenzyme was initiated. 1,3-Dimethylimidazolidine as a new tetrahydrofolate coenzyme model at formaldehyde oxidation level was used to react with ketone having active hydrogen atoms and amine to give the corresponding Mannich base in good yield by a covert Mannich reaction. A novel method for biomimetic synthesis of various Mannich bases is provided.展开更多
基金Project supported by the Chinese Science Foundation and Shanxi Provincial Science Foundation.
文摘Tetrahydrofolate (THF) coenzymes are involved in biochemical transfer of aone-carbon fragment at different oxidation levels. The study of THF models may providea valuable class of reagents for group transfer reactions with practical significance. Onlya few researches about 5, 10-methenyl-THF models have been reported in literature.
基金This work was supported by the Science Foundation of Shanxi Province.
文摘Four 1, 2, 3-trisubstituted imidazolinium iodides which were used as 5,10-^+CPh-THF model (7-10) at formic acid oxidation level were synthesized. The benzylidyne group (phenyl- substituted one carbon unit)transfer reactions from these compounds to Grignard reagent were in- vestigated, and the reactions of these compounds with KBH_4 and NaOH were also studied.
文摘Photocatalytic oxidation of primary and secondary benzyl alcohol to corresponding benzaldehyde or acetophenone using Acr+Cl04- or PhAcr+Cl04- as photocatalysts under visible light irradiation at room temperature.
基金This work was supported by the National Natural Science Foundation of China(NO.20172041)Provincial Natural Science Foundation of Shaanxi Province.
文摘The addition-hydrolysis reaction of benzimidazolium salt with some mono- and bifunctional amine nucleophiles is reported, and a novel method of biomimetic synthesis for formamides and heterocycle compounds is provided.
基金Project supported by the National Natural Science Foundation of China (No. 20072036) and the Specialized Research Fund for the Doctoral Program of Higher Education of China.Acknowledgment We would like to thank Professor Yun-Dong Wu of the Hong Kong University of Science and Technology and Peking University for helpful advice.
文摘An efficient method for the selective hydrogenation of a series of α,β-epoxyketones to β-hydroxyketones using catalytic amount of two sulfinyl analogues of NAD^+ model compounds is reported. The lack of any diastereoselectivity for the formation of β-hydroxyketones with optically pure sulfinyl analogue of NAD^+ model supports the radical mechanism proposed previously.
基金support from the National Natural Science Foundation of China(21072104, 20921120403 and 20832004)the National Basic Research Program of China (2004CB719905)the 111 Project (B06005) is gratefully acknowledged
文摘Heterolytic and homolytic C D bond dissociation energies of three NADH models: BNAH-4,4-d 2 , HEH-4,4-d 2 and AcrD 2 in acetonitrile were first estimated by using an efficient method. The results showed that the heterolytic C D bond dissociation energies are 65.2, 70.2, and 81.9 kcal/mol and the homolytic C D bond dissociation energies are 72.66, 70.69, and 74.95 kcal/mol for BNAH-4,4-d 2 , HEH-4,4-d 2 , and AcrD 2 , respectively. According to the bond dissociation energy differences of isotope isomers, an interesting conclusion can be made that the primary kinetic isotope effects are dependent not only on the zero-point energy difference of the isotope isomers, but also on the types of C D bond dissociations, and the C D bond homolytic dissociations should have much larger primary kinetic isotope effects (26.9 28.8) than the corresponding C D bond heterolytic dissociations (3.9-5.4).
基金Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/cjoc.201100628 or from the author.Acknowledgement We are very grateful for the support of this work from the National Natural Science Foundation of China (Nos. 20802056, 21072158) and the Special Foundation of the Education Committee of Shaanxi Province (No. 09JK750).
文摘Since the early studies of Mannich, Mannich reaction has become an important tool for the synthesis of new compounds. Mannich bases can be either directly employed or used as intermediates. In this work, the one-carbon unit transfer reaction of tetrahydrofolate coenzyme was initiated. 1,3-Dimethylimidazolidine as a new tetrahydrofolate coenzyme model at formaldehyde oxidation level was used to react with ketone having active hydrogen atoms and amine to give the corresponding Mannich base in good yield by a covert Mannich reaction. A novel method for biomimetic synthesis of various Mannich bases is provided.