A novel and facile method for selective ortho-C--H monofluorination of aniline derivatives was achieved using Selectfluor/Cu（OAc）JHOAc system. The reaction proceeded via electrophilic process with diverse substrates...A novel and facile method for selective ortho-C--H monofluorination of aniline derivatives was achieved using Selectfluor/Cu（OAc）JHOAc system. The reaction proceeded via electrophilic process with diverse substrates in acceptable moderate to high yields. The position selectivity was controlled by bidentate coordination of picolinic acid amides with copper.展开更多
Two new compounds Cu(pic)2[CO(NH2)2]2 1 and (picH2)2[Cu(pic)2(SCN)2] 2 were prepared from the reaction of picolinic acid and copper(II) per-chlorate by using carbamide to adjust pH = 4 in the preparation of compound 1...Two new compounds Cu(pic)2[CO(NH2)2]2 1 and (picH2)2[Cu(pic)2(SCN)2] 2 were prepared from the reaction of picolinic acid and copper(II) per-chlorate by using carbamide to adjust pH = 4 in the preparation of compound 1 and KSCN to adjust pH = 6 in the preparation of 2. Crystal data for 1: monoclinic system, space group P21/n with a = 7.441(1), b = 14.291(2), c = 7.790(1) ? b = 95.855(2), V = 824.0(2) ?, Dc = 1.724 g/cm3, F(000) = 438, C14H16N6O6Cu, Mr = 427.87, m(MoKa) = 1.375 mm-1, Z = 2 and the final R = 0.0365 for 1164 observed reflections. Crystal data for 2: monoclinic system, space group P21/c with a = 9.8237(3), b = 10.0409(3), c = 14.5867(2) ? b = 104.190(2), V = 1394.91(6) ?, Dc = 1.595 g/cm3, F(000) = 686, C26H20N6O8S2Cu, Mr = 672.14, m(MoKa) = 0.994 mm-1, Z = 2 and the final R = 0.0442 for 1651 observed reflections. The Cu(II) atom in both 1 and 2 has a 4+2 elongated octahedral environment with the pic ligands locating on the equatorial plane, and carbamide and SCN occupying the axial sites, respectively. In compound 2, there also exist two protonated picolinate cations for charge balance.展开更多
Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclin...Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclinic, space group C2/c, with a = 24.144(5), b = 7.1622(14), c = 17.283(4) ?, C16H24Cu2N4O12, Mr = 591.47, β = 131.73(3)o, V = 2230.3(8) ?3, Z = 4, Dc = 1.761 g/cm3, F(000) = 1208, μ = 1.978 mm?1, R = 0.0400 and wR = 0.1099. The copper (II) ion is five- coordinated with a distorted square pyramidal geometry. The complex can be viewed as a one- dimensional chain structure by carboxylic bridges among copper atoms. In the complex there exist hydrogen bonding interactions to stabilize the structure.展开更多
Although prostate epithelium concentrates zinc for the purpose of promoting citrate secretion,it loses its capacity to import zinc while undergoing malignant transformation.This exclusion of zinc may be necessary for ...Although prostate epithelium concentrates zinc for the purpose of promoting citrate secretion,it loses its capacity to import zinc while undergoing malignant transformation.This exclusion of zinc may be necessary for the viability of prostate cancer,as measures which increase the intracellular zinc content of prostate cancers lead to cell death,oxidative stress,and a marked reduction in ATP,suggestive of mitochondrial damage.The anti-fungal drug clioquinol,which can act as a zinc ionophore,can markedly slow the growth of human prostate cancer in nude mice,and has been proposed as a clinical therapy for prostate cancer.However,clioquinol is currently only available as a topical agent,as it was linked to subacute myelo-optic neuropathy with oral use.A more practical option for promoting zinc transport may be offered by the nutraceutical zinc dipicolinate,a stable chelate in which four coordination positions of zinc are occupied by two molecules of the tryptophan metabolite picolinic acid.Zinc dipicolinate is a highly effective supplemental source of zinc that has been shown to be more potent than soluble zinc salts for alleviating the symptoms of acrodermatitis enteropathica,a genetic zinc deficiency disorder reflecting homozygous loss of functional ZIP4 zinc importers in enterocytes.This suggests that the zinc dipicolinate complex is sufficiently stable and lipophilic to transfer zinc across cellular membranes.If so,it may have potential for“smuggling”zinc into prostate cancer cells.Hence,cell culture and rodent studies to evaluate the impact of zinc dipicolinate on human prostate cancer are warranted.展开更多
文摘A novel and facile method for selective ortho-C--H monofluorination of aniline derivatives was achieved using Selectfluor/Cu（OAc）JHOAc system. The reaction proceeded via electrophilic process with diverse substrates in acceptable moderate to high yields. The position selectivity was controlled by bidentate coordination of picolinic acid amides with copper.
基金This work was supported by the National Natural Science Foundation of China (20001007 20131020) Natural Science Foundation of the Chinese Academy of Sciences (KJCX2-H3) and Fujian province (2000F006)
文摘Two new compounds Cu(pic)2[CO(NH2)2]2 1 and (picH2)2[Cu(pic)2(SCN)2] 2 were prepared from the reaction of picolinic acid and copper(II) per-chlorate by using carbamide to adjust pH = 4 in the preparation of compound 1 and KSCN to adjust pH = 6 in the preparation of 2. Crystal data for 1: monoclinic system, space group P21/n with a = 7.441(1), b = 14.291(2), c = 7.790(1) ? b = 95.855(2), V = 824.0(2) ?, Dc = 1.724 g/cm3, F(000) = 438, C14H16N6O6Cu, Mr = 427.87, m(MoKa) = 1.375 mm-1, Z = 2 and the final R = 0.0365 for 1164 observed reflections. Crystal data for 2: monoclinic system, space group P21/c with a = 9.8237(3), b = 10.0409(3), c = 14.5867(2) ? b = 104.190(2), V = 1394.91(6) ?, Dc = 1.595 g/cm3, F(000) = 686, C26H20N6O8S2Cu, Mr = 672.14, m(MoKa) = 0.994 mm-1, Z = 2 and the final R = 0.0442 for 1651 observed reflections. The Cu(II) atom in both 1 and 2 has a 4+2 elongated octahedral environment with the pic ligands locating on the equatorial plane, and carbamide and SCN occupying the axial sites, respectively. In compound 2, there also exist two protonated picolinate cations for charge balance.
文摘Using Cu(II) as the template, a complex {[Cu2L2(H2O)2]·4H2O}n (L = N-acetoxyl- picolinamide) has been successfully synthesized and characterized by single-crystal X-ray diffrac- tion. The crystal is of monoclinic, space group C2/c, with a = 24.144(5), b = 7.1622(14), c = 17.283(4) ?, C16H24Cu2N4O12, Mr = 591.47, β = 131.73(3)o, V = 2230.3(8) ?3, Z = 4, Dc = 1.761 g/cm3, F(000) = 1208, μ = 1.978 mm?1, R = 0.0400 and wR = 0.1099. The copper (II) ion is five- coordinated with a distorted square pyramidal geometry. The complex can be viewed as a one- dimensional chain structure by carboxylic bridges among copper atoms. In the complex there exist hydrogen bonding interactions to stabilize the structure.
文摘Although prostate epithelium concentrates zinc for the purpose of promoting citrate secretion,it loses its capacity to import zinc while undergoing malignant transformation.This exclusion of zinc may be necessary for the viability of prostate cancer,as measures which increase the intracellular zinc content of prostate cancers lead to cell death,oxidative stress,and a marked reduction in ATP,suggestive of mitochondrial damage.The anti-fungal drug clioquinol,which can act as a zinc ionophore,can markedly slow the growth of human prostate cancer in nude mice,and has been proposed as a clinical therapy for prostate cancer.However,clioquinol is currently only available as a topical agent,as it was linked to subacute myelo-optic neuropathy with oral use.A more practical option for promoting zinc transport may be offered by the nutraceutical zinc dipicolinate,a stable chelate in which four coordination positions of zinc are occupied by two molecules of the tryptophan metabolite picolinic acid.Zinc dipicolinate is a highly effective supplemental source of zinc that has been shown to be more potent than soluble zinc salts for alleviating the symptoms of acrodermatitis enteropathica,a genetic zinc deficiency disorder reflecting homozygous loss of functional ZIP4 zinc importers in enterocytes.This suggests that the zinc dipicolinate complex is sufficiently stable and lipophilic to transfer zinc across cellular membranes.If so,it may have potential for“smuggling”zinc into prostate cancer cells.Hence,cell culture and rodent studies to evaluate the impact of zinc dipicolinate on human prostate cancer are warranted.
