Chloropcroxidase （CPO） was immobilized by konjac glucomannan （KGM） on the 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4]/Nafion modified glassy carbon eloctrode. The electrochemical behaviors of the im...Chloropcroxidase （CPO） was immobilized by konjac glucomannan （KGM） on the 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4]/Nafion modified glassy carbon eloctrode. The electrochemical behaviors of the immobilized CPO were investigated by cyclic voltammetry. The results showed that CPO was successfully immobilized on the GCE and underwent fast direct electron transfer reactions with the formal potential at -0.3 V vs. SCE. The modified electrode showed a good catalytic activity for elcctrocatalytical reduction of O2 and H2O2.展开更多
Poly-L-lysine(PLL) was first electrodeposited onto the surface of a glassy carbon(GC) electrode.The PLL modified electrode was used to immobilize chloroperoxidase(CPO) via 1-[(3-dimethylamino)propyl]-3-ethylcarbodiimi...Poly-L-lysine(PLL) was first electrodeposited onto the surface of a glassy carbon(GC) electrode.The PLL modified electrode was used to immobilize chloroperoxidase(CPO) via 1-[(3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride(EDC).The electrochemical behaviors of immobilized CPO on PLL/GC electrode were investigated by cyclic voltammetry(CV).The CV results obtained showed that CPO was successfully immobilized on the PLL/GC electrode and a fast direct electron transfer between CPO and PLL-GC electrod...展开更多
A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing t...A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing the triflate anion with Cl^(-)or Br^(-),we were able to halogenate toluene with high selectivity for C(sp^(2))-H bonds over C(sp^(3))-H bonds,such as chlorination with Cl^(-)or bromination with Br^(-)in the aromatic ring.We have also examined the halogenation of naphthalene and benzene derivatives with[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)(X=Cl^(-)and Br^(-)).In all of these reactions,halogenated products were formed dominantly,and the source of the halogens in the products was found to be halides present in the[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)complexes.In the absence of halides,naphthalene was found to undergo dimerization.Kinetic isotope effect(KIE)experiments on this reaction showed no isotopic effect in the halogenation reactions.DFT calculations on models with the naphthalene substrate supported a mechanism involving an initial(rate-limiting)electron transfer from the substrate to[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+),coupled by the attachment of Cl^(-)to the C1 position of the naphthalene radical cation.This mechanism was also supported by the Marcus theory of outer-sphere electron transfer.The so-formed[Mn^(IV)(OH)(Por)(OTf)](a manganese compound II analogue)underwent a hydrogen atom transfer from the C1 position of the substrate to form chlorinated naphthalene and[Mn^(III)(H_(2)O)(Por)(OTf)].DFT calculations showed that[Mn^(IV)(OH)(Por)(OTf)]can also undergo direct OH-transfer to the substrate competitively,leaving open possibilities for side reactions or alternative reactions in a different environment.This study provides a deeper understanding of chloroperoxidase-like reactions.展开更多
Enzymatic reactions take place with high chemo-, regio-, and stereo-selectivity, appealing for the direct functionalization of abundant and inexpensive compounds with C-H bonds to make fine chemicals such as high-valu...Enzymatic reactions take place with high chemo-, regio-, and stereo-selectivity, appealing for the direct functionalization of abundant and inexpensive compounds with C-H bonds to make fine chemicals such as high-value intermediates and pharmaceuticals. This review summarizes recent progress in the enzymatic functionalization of C-H bonds with an emphasis on heme enzymes such as cytochrome P450 s, chloroperoxidase and unspecific peroxygenases. Specific examples are discussed to elucidate the applications of the molecular and process engineering approaches to overcome the challenges hindering enzymatic C-H functionalization. Also discussed is the recent development of the chemo-enzymatic cascade as an effective way to integrate the power of metal catalysis and enzymatic catalysis for C-H functionalization.展开更多
The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocata...The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocatalysis to propose a new route for the chiral epoxidation of styrene and its derivatives.Chloroperoxidase(CPO)functionalized with 1-ethyl-3-methylimidazolium bromide(ILEMB)was loaded onto cobalt nitrogen-doped carbon nanotubes(CoN@CNT)to form a biohybrid(CPO-ILEMB/CoN@CNT).H_(2)O_(2)species were generated in situ through a two-electron oxygen reduction reaction(2e–ORR)at CoN@CNT to initiate the following enzymatic epoxidation of styrene by CPO.CoN@CNT had high electroactivity for the ORR to produce H_(2)O_(2)at a more positive potential,prohibiting the conversion of FeⅢ to FeⅡ in the heme of CPO to maintain enzymatic activity.Meanwhile,CoN@CNT could serve as an ideal carrier for the immobilization of CPO-ILEMB.Hence,the coimmobilization of CPO-ILEMB and CoN@CNT could facilitate the diffusion of intermediate H_(2)O_(2),which achieved 17 times higher efficiency than the equivalent amounts of free CPO-ILEMB in bulk solution for styrene epoxidation.Notably,an enhancement(~45%)of chiral selectivity for the epoxidation of styrene was achieved.展开更多
基金supported by grants from National Natural Science Foundation of China (No.20503016,20775049).
文摘Chloropcroxidase （CPO） was immobilized by konjac glucomannan （KGM） on the 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF4]/Nafion modified glassy carbon eloctrode. The electrochemical behaviors of the immobilized CPO were investigated by cyclic voltammetry. The results showed that CPO was successfully immobilized on the GCE and underwent fast direct electron transfer reactions with the formal potential at -0.3 V vs. SCE. The modified electrode showed a good catalytic activity for elcctrocatalytical reduction of O2 and H2O2.
基金supported by grant from National Natural Science Foundation of China(No.20775049).
文摘Poly-L-lysine(PLL) was first electrodeposited onto the surface of a glassy carbon(GC) electrode.The PLL modified electrode was used to immobilize chloroperoxidase(CPO) via 1-[(3-dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride(EDC).The electrochemical behaviors of immobilized CPO on PLL/GC electrode were investigated by cyclic voltammetry(CV).The CV results obtained showed that CPO was successfully immobilized on the PLL/GC electrode and a fast direct electron transfer between CPO and PLL-GC electrod...
基金supported by the NRF of Korea(NRF-2021R1A3B1076539 and NRF-2023K2A9A2A11098996 to W.N.,NRF-2023R1A2C1007668 to Y.-M.L.and RS-2021-NR058689 to K.-B.C.)the MoE G-LAMP Program(No.RS-2024-00443714 to K.-B.C)the Henan Center for Outstanding Overseas Scientists,China(GZS2024020 to W.N.).
文摘A high-valent manganese(IV)-hydroxo porphyrinπ-cation radical complex,[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+)(a protonated manganese compound I analogue),was studied in the halogenation of aromatic compounds.By replacing the triflate anion with Cl^(-)or Br^(-),we were able to halogenate toluene with high selectivity for C(sp^(2))-H bonds over C(sp^(3))-H bonds,such as chlorination with Cl^(-)or bromination with Br^(-)in the aromatic ring.We have also examined the halogenation of naphthalene and benzene derivatives with[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)(X=Cl^(-)and Br^(-)).In all of these reactions,halogenated products were formed dominantly,and the source of the halogens in the products was found to be halides present in the[Mn^(IV)(OH)(Por^(˙+))(X)]^(+)complexes.In the absence of halides,naphthalene was found to undergo dimerization.Kinetic isotope effect(KIE)experiments on this reaction showed no isotopic effect in the halogenation reactions.DFT calculations on models with the naphthalene substrate supported a mechanism involving an initial(rate-limiting)electron transfer from the substrate to[Mn^(IV)(OH)(Por^(˙+))(OTf)]^(+),coupled by the attachment of Cl^(-)to the C1 position of the naphthalene radical cation.This mechanism was also supported by the Marcus theory of outer-sphere electron transfer.The so-formed[Mn^(IV)(OH)(Por)(OTf)](a manganese compound II analogue)underwent a hydrogen atom transfer from the C1 position of the substrate to form chlorinated naphthalene and[Mn^(III)(H_(2)O)(Por)(OTf)].DFT calculations showed that[Mn^(IV)(OH)(Por)(OTf)]can also undergo direct OH-transfer to the substrate competitively,leaving open possibilities for side reactions or alternative reactions in a different environment.This study provides a deeper understanding of chloroperoxidase-like reactions.
基金Supported by the National Natural Science Foundation of China(No.21676157 and No.21520102008)。
文摘Enzymatic reactions take place with high chemo-, regio-, and stereo-selectivity, appealing for the direct functionalization of abundant and inexpensive compounds with C-H bonds to make fine chemicals such as high-value intermediates and pharmaceuticals. This review summarizes recent progress in the enzymatic functionalization of C-H bonds with an emphasis on heme enzymes such as cytochrome P450 s, chloroperoxidase and unspecific peroxygenases. Specific examples are discussed to elucidate the applications of the molecular and process engineering approaches to overcome the challenges hindering enzymatic C-H functionalization. Also discussed is the recent development of the chemo-enzymatic cascade as an effective way to integrate the power of metal catalysis and enzymatic catalysis for C-H functionalization.
基金supported by the National Natural Science Foundation of China(22273056)the Science and Technology Innovation Team of Shaanxi Province(2023-CX-TD-27)the Fundamental Research Funds for the Central Universities(GK202202001).
文摘The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocatalysis to propose a new route for the chiral epoxidation of styrene and its derivatives.Chloroperoxidase(CPO)functionalized with 1-ethyl-3-methylimidazolium bromide(ILEMB)was loaded onto cobalt nitrogen-doped carbon nanotubes(CoN@CNT)to form a biohybrid(CPO-ILEMB/CoN@CNT).H_(2)O_(2)species were generated in situ through a two-electron oxygen reduction reaction(2e–ORR)at CoN@CNT to initiate the following enzymatic epoxidation of styrene by CPO.CoN@CNT had high electroactivity for the ORR to produce H_(2)O_(2)at a more positive potential,prohibiting the conversion of FeⅢ to FeⅡ in the heme of CPO to maintain enzymatic activity.Meanwhile,CoN@CNT could serve as an ideal carrier for the immobilization of CPO-ILEMB.Hence,the coimmobilization of CPO-ILEMB and CoN@CNT could facilitate the diffusion of intermediate H_(2)O_(2),which achieved 17 times higher efficiency than the equivalent amounts of free CPO-ILEMB in bulk solution for styrene epoxidation.Notably,an enhancement(~45%)of chiral selectivity for the epoxidation of styrene was achieved.
