1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of pr...1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.展开更多
The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on th...The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.展开更多
The synthesis of a novel α phosphorus containing spin trap, DEPDMPO(5 diethoxy Phosphoryl 2, 5 dimethyl 1 pyrroline \%N\% oxide) and the evaluation of its ability to spin trap the hydroxyl and the superoxide anion ra...The synthesis of a novel α phosphorus containing spin trap, DEPDMPO(5 diethoxy Phosphoryl 2, 5 dimethyl 1 pyrroline \%N\% oxide) and the evaluation of its ability to spin trap the hydroxyl and the superoxide anion radicals were described in the present article. The ability to trap an active superoxide anion radical generated in the photo system Ⅱ(PSII) and the stability of their spin adduct of DEPDMPO as well as three previously reported traps DMPO, DEPMPO and M 3PO were comparatively analyzed according to their chemical structures. In addition, the effects of 2 methyl and \%α\% phosphoryl substituted analogues of DMPO on the stabilities of the corresponding spin adduts were systematically展开更多
Synthesis of a novel α phosphorus containing spin trap, DEPPEPO[5 (diethoxyphosphoryl) 5 phenylethyl 1 pyrroline] N oxide and evaluation of its ability to spin trap the hydroxyl and the superoxide anion radicals were...Synthesis of a novel α phosphorus containing spin trap, DEPPEPO[5 (diethoxyphosphoryl) 5 phenylethyl 1 pyrroline] N oxide and evaluation of its ability to spin trap the hydroxyl and the superoxide anion radicals were described in the present article. The ability for trapping an active superoxide anion radicals generated in the HX/XO system and the stability of their spin adduct of DEPPEPO were analyzed. In addition, the effects of 5 phenylethyl and 5 phenyl substituted analogues of DMPO on the stereochemistry of the corresponding spin adducts were systematically illustrated.展开更多
L-Tyr-EMPO,a new EMPO analogue bearing an L-tyrosine methyl ether group,was first synthesized by acylation.Various radicals,including O-·2,·OH,·OR,and ·R,have been efficiently detected and characte...L-Tyr-EMPO,a new EMPO analogue bearing an L-tyrosine methyl ether group,was first synthesized by acylation.Various radicals,including O-·2,·OH,·OR,and ·R,have been efficiently detected and characterized via L-Tyr-EMPO.The half-life of the L-Tyr-EMPO superoxide adduct was estimated to be ca.6.5 min.More importantly,the present study demonstrated a new synthetic strategy for covalent conjugation between cyclic-nitrone and amino group in peptides or proteins,by which the site-specifically spin trapping can be performed via antibody linked nitrone in the near future.Furthermore,with the help of the covalent link,the targeting for the areas of interest in which the monitored radical species was sitespecially generated.展开更多
基金This work was supported by the NNSFC (No.29672004).
文摘1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
基金the National Natural Science Foundation of China(No.22071035)the Natural Science Foundation of Guangxi(Nos.2023GXNSFDA026025,2022GXNSFBA035494)+2 种基金Guangxi Minzu University Scientific Research Funds for Talent Introduction(2022KJQD14)the Student Innovation Training Program(No.202310602014)are greatly appreciated.
文摘The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.
文摘The synthesis of a novel α phosphorus containing spin trap, DEPDMPO(5 diethoxy Phosphoryl 2, 5 dimethyl 1 pyrroline \%N\% oxide) and the evaluation of its ability to spin trap the hydroxyl and the superoxide anion radicals were described in the present article. The ability to trap an active superoxide anion radical generated in the photo system Ⅱ(PSII) and the stability of their spin adduct of DEPDMPO as well as three previously reported traps DMPO, DEPMPO and M 3PO were comparatively analyzed according to their chemical structures. In addition, the effects of 2 methyl and \%α\% phosphoryl substituted analogues of DMPO on the stabilities of the corresponding spin adduts were systematically
文摘Synthesis of a novel α phosphorus containing spin trap, DEPPEPO[5 (diethoxyphosphoryl) 5 phenylethyl 1 pyrroline] N oxide and evaluation of its ability to spin trap the hydroxyl and the superoxide anion radicals were described in the present article. The ability for trapping an active superoxide anion radicals generated in the HX/XO system and the stability of their spin adduct of DEPPEPO were analyzed. In addition, the effects of 5 phenylethyl and 5 phenyl substituted analogues of DMPO on the stereochemistry of the corresponding spin adducts were systematically illustrated.
文摘L-Tyr-EMPO,a new EMPO analogue bearing an L-tyrosine methyl ether group,was first synthesized by acylation.Various radicals,including O-·2,·OH,·OR,and ·R,have been efficiently detected and characterized via L-Tyr-EMPO.The half-life of the L-Tyr-EMPO superoxide adduct was estimated to be ca.6.5 min.More importantly,the present study demonstrated a new synthetic strategy for covalent conjugation between cyclic-nitrone and amino group in peptides or proteins,by which the site-specifically spin trapping can be performed via antibody linked nitrone in the near future.Furthermore,with the help of the covalent link,the targeting for the areas of interest in which the monitored radical species was sitespecially generated.
