Toluene-3,4-diamine was prepared by catalytical hydrogenation of 2-nitro-4-aminotoluene at atmospheric pressure and 40 ℃ in the presence of catalyst Urushibara-Ni in yield of 84.7%. The catalyst can be reused 10 times.
合成了N-［(2-羟基-5-甲基苯)（苯基）］亚甲基邻苯二胺，晶体属单斜晶系，空 间群P21/c. 晶胞参数 a = 1.034 0(6) nm， b =1.092 0(3) nm， c =1.472 0(4) nm, β = 107.89(3)°, 化学式C20H18N2O, M r =302.36， Z =4, V =1.581 ...合成了N-［(2-羟基-5-甲基苯)（苯基）］亚甲基邻苯二胺，晶体属单斜晶系，空 间群P21/c. 晶胞参数 a = 1.034 0(6) nm， b =1.092 0(3) nm， c =1.472 0(4) nm, β = 107.89(3)°, 化学式C20H18N2O, M r =302.36， Z =4, V =1.581 7(10) nm3 ， D c = 1.268 g/cm3， F （000）= 160，最终偏离因子 R1 = 0.054 1. 结构分析表明，分子间以氢键形成二聚体，二聚体 的分子间互为中心对称. 循环伏安法表明标题化合物的电极反应是一个不可逆的单电子传荷 过程.展开更多
Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated ...Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.展开更多
Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediate...Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediates for organic synthesis and industrial processes.Among the developed oxidationprotocols,innovative strategies using hydroxyimide organocatalysts in combination with metallicor metal‐free cocatalysts have attracted much attention because of the good activities andselectivities of such catalysts in the oxo functionalization of hydrocarbons.This method is based onthe reaction using N‐hydroxyphthalimide,which was first reported by Ishii’s group in the1990s.Although the important and wide‐ranging applications of such catalysts have been summarizedrecently,there are no reviews that focus solely on oxidation strategies using multi‐nitroxy organocatalysts,which have interesting properties and high reactivities.This review covers the concisesynthetic methods and mechanistic profiles of known multi‐nitroxy organocatalysts and summarizessignificant advances in their use in efficient aerobic oxidation.Based on a combination of experimentaland theoretical results,guidelines for the future rational design of multi‐nitroxy organocatalystsare proposed,and the properties of various model multi‐nitroxy organocatalysts are predicted.The present overview of the advantages,limitations,and potential applications of multi‐nitroxyorganocatalysts can provide useful tools for researchers in the field of selective oxidation.展开更多
Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) phot...Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) photocatalysis.Herein,we utilized N‐hydroxyphthalimide(NHPI)as the probe molecule to distinguish the role of different NbO_(x) units in the activation of C–H bond under visible light irradia‐tion.With the addition of NHPI,Nb_(2)O_(5) catalysts with highly disordered NbO_(6) units exhibited higher activities than that with slightly disordered NbO_(6) units(419‒495 vs.82μmol·g^(-1)·h^(-1))in photocata‐lytic selective oxidation of ethylbenzene.Revealed by Raman spectra,electron paramagnetic reso‐nance spectra,and transmission‐electron‐microscopy images,highly disordered NbO_(6) units were confirmed to act as the active sites for the transfer of photogenerated electrons from NHPI,pro‐moting the generation of phthalimide‐N‐oxyl(PINO)radicals for the enhanced conversion of ethylbenzene under visible light irradiation.This study provides guidance on the role of local NbO_(x) units in Nb_(2)O_(5) photocatalysis.展开更多
The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-...The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.展开更多
As benzoxazin-4-ones and quinazolines linked to indole nucleus acting as a good pharmacophore, the synthesis of these compounds has significant meaning. The key intermediates 2-（2＇, 5＇-disubstituted-indol-2＇-yl...As benzoxazin-4-ones and quinazolines linked to indole nucleus acting as a good pharmacophore, the synthesis of these compounds has significant meaning. The key intermediates 2-（2＇, 5＇-disubstituted-indol-2＇-yl）-4H-3, 1-benzoxazin-4-ones （3） were synthesized from cyclocondensation of indole-2-carbonyl chlorides （2） and anthranilic acid. Compound （3） on reaction with thiosemicarbazide and o-phenylene diamine afforded the compound （4） and （6） respectively. Compound （4） subjected to intramolecular cyclization under thermal conditions above its melting point afforded the compound （5）. Similarly compound （3） on fusion with o- phenylene diamine gave compound （7）. Structures of these compounds were confirmed by their spectral studies. The compounds were screened for their antimicrobial activity and the results were reported.展开更多
文摘Toluene-3,4-diamine was prepared by catalytical hydrogenation of 2-nitro-4-aminotoluene at atmospheric pressure and 40 ℃ in the presence of catalyst Urushibara-Ni in yield of 84.7%. The catalyst can be reused 10 times.
文摘合成了N-［(2-羟基-5-甲基苯)（苯基）］亚甲基邻苯二胺，晶体属单斜晶系，空 间群P21/c. 晶胞参数 a = 1.034 0(6) nm， b =1.092 0(3) nm， c =1.472 0(4) nm, β = 107.89(3)°, 化学式C20H18N2O, M r =302.36， Z =4, V =1.581 7(10) nm3 ， D c = 1.268 g/cm3， F （000）= 160，最终偏离因子 R1 = 0.054 1. 结构分析表明，分子间以氢键形成二聚体，二聚体 的分子间互为中心对称. 循环伏安法表明标题化合物的电极反应是一个不可逆的单电子传荷 过程.
文摘Homogeneous and heterogeneous types of catalysis are frequently considered as separate disciplines or even opposed to each other.In the present work,a new type of mixed het-ero-/homogeneous catalysis was demonstrated for the case of selective alkylarene oxidation by molecular oxygen.The proposed catalytic system consists of two widely available components:N-hydroxyphthalimide(NHPI,a homogeneous organocatalyst for free-radical chain reactions)and nanosized TiO_(2)(heterogeneous UV-active photoredox catalyst).The interaction of NHPI with TiO_(2) allows for a shift from UV to visible light photoredox activity and generation of phthalimide-N-oxyl(PINO)radicals that diffuse into the solution where NHPI/PINO-catalyzed free-radical chain reaction can proceed without the additional light input providing a fundamental increase in energy efficiency.The NHPI/TiO_(2) ratio controls the selectivity of oxidation affording preferential formation of hydroperoxide or ketone from alkylarene.
基金supported by the China Postdoctoral Science Foundation (2014M551746)~~
文摘Selective oxidation with molecular oxygen as the sole oxidant under mild conditions is of crucialimportance for the long‐term sustainable exploitation of available feedstocks and the formation ofrequired intermediates for organic synthesis and industrial processes.Among the developed oxidationprotocols,innovative strategies using hydroxyimide organocatalysts in combination with metallicor metal‐free cocatalysts have attracted much attention because of the good activities andselectivities of such catalysts in the oxo functionalization of hydrocarbons.This method is based onthe reaction using N‐hydroxyphthalimide,which was first reported by Ishii’s group in the1990s.Although the important and wide‐ranging applications of such catalysts have been summarizedrecently,there are no reviews that focus solely on oxidation strategies using multi‐nitroxy organocatalysts,which have interesting properties and high reactivities.This review covers the concisesynthetic methods and mechanistic profiles of known multi‐nitroxy organocatalysts and summarizessignificant advances in their use in efficient aerobic oxidation.Based on a combination of experimentaland theoretical results,guidelines for the future rational design of multi‐nitroxy organocatalystsare proposed,and the properties of various model multi‐nitroxy organocatalysts are predicted.The present overview of the advantages,limitations,and potential applications of multi‐nitroxyorganocatalysts can provide useful tools for researchers in the field of selective oxidation.
文摘Although different NbO_(x) units are present in Nb_(2)O_(5)‐based catalysts,the correlations between these structures and activity remain unclear,which considerably hinders the further development of Nb_(2)O_(5) photocatalysis.Herein,we utilized N‐hydroxyphthalimide(NHPI)as the probe molecule to distinguish the role of different NbO_(x) units in the activation of C–H bond under visible light irradia‐tion.With the addition of NHPI,Nb_(2)O_(5) catalysts with highly disordered NbO_(6) units exhibited higher activities than that with slightly disordered NbO_(6) units(419‒495 vs.82μmol·g^(-1)·h^(-1))in photocata‐lytic selective oxidation of ethylbenzene.Revealed by Raman spectra,electron paramagnetic reso‐nance spectra,and transmission‐electron‐microscopy images,highly disordered NbO_(6) units were confirmed to act as the active sites for the transfer of photogenerated electrons from NHPI,pro‐moting the generation of phthalimide‐N‐oxyl(PINO)radicals for the enhanced conversion of ethylbenzene under visible light irradiation.This study provides guidance on the role of local NbO_(x) units in Nb_(2)O_(5) photocatalysis.
基金supported by the National Natural Science Foundation of China(Grant No.20072025).
文摘The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.
文摘As benzoxazin-4-ones and quinazolines linked to indole nucleus acting as a good pharmacophore, the synthesis of these compounds has significant meaning. The key intermediates 2-（2＇, 5＇-disubstituted-indol-2＇-yl）-4H-3, 1-benzoxazin-4-ones （3） were synthesized from cyclocondensation of indole-2-carbonyl chlorides （2） and anthranilic acid. Compound （3） on reaction with thiosemicarbazide and o-phenylene diamine afforded the compound （4） and （6） respectively. Compound （4） subjected to intramolecular cyclization under thermal conditions above its melting point afforded the compound （5）. Similarly compound （3） on fusion with o- phenylene diamine gave compound （7）. Structures of these compounds were confirmed by their spectral studies. The compounds were screened for their antimicrobial activity and the results were reported.
