A novel nitrogen‐centered radical‐induced1,2‐carbon migration reaction of allylic alcohols has been developed.This method provides easy access to a variety ofα‐quaternary‐β‐amino ketones under mild reaction co...A novel nitrogen‐centered radical‐induced1,2‐carbon migration reaction of allylic alcohols has been developed.This method provides easy access to a variety ofα‐quaternary‐β‐amino ketones under mild reaction conditions.The reaction has a wide substrate scope and operational simplicity.Mechanistic studies suggest that1,2‐carbon migration is induced by regioselective nitrogen‐centered radical addition to the alkene unit.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.展开更多
Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, ...Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, followed by selenoxide syn-elimination and [2,3] sigmatropic rearrangement respectively to give Z-allylic alcohols stereoselectively.展开更多
Allylic alcohols react with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound bidentate sulfur palladium (0) complex to form 3-arylaldehydes or ketones in good yields.
A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step economy.This pr...A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step economy.This protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild conditions.Further transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product analogues.Experimental studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and enantioselectivity.The density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.展开更多
Introduction: Surgical site infections (SSIs) remain the most common health care associated infections in the surgical population. Preoperative surgical preparation solutions containing alcohol are believed to be best...Introduction: Surgical site infections (SSIs) remain the most common health care associated infections in the surgical population. Preoperative surgical preparation solutions containing alcohol are believed to be best at eradicating skin microorganisms. The efficacy of alcohol is concentration dependant, with a concentration of greater than 60% most bactericidal. Surgical antisepsis guidelines do not stipulate how long alcoholic preparation solutions can be left out prior to use. Method: 30 ml of Alcoholic Iodine (Iodine 1% in Alcohol 70% (v/v)) and Alcoholic Chlorhexidine (Chlorhex-idine 2% in Alcohol 70% (v/v)) were left to stand in gallipots in an operating theatre equipped with laminar flow. Sam-ples were taken at 0, 30, 60 and 120 minutes and the alcohol content was analyzed. The experiment was repeated 3 times for each time interval. Results: The Alcoholic Iodine group demonstrated significant decrease in alcohol concen-tration, from a mean of 76% (SD 3.6) to a mean of 37.7% (SD 2.9) in only 30 minutes. This effect was sustained, reaching a mean concentration of 26% (SD 2.9) alcohol at 120 minutes. The Alcoholic Chlorhexidine group did not exhibit the same degree of concentration drop, the concentration dropped marginally to 71.5% (SD 2.7) at 120 minutes from 83.4% (SD 0.4). Conclusion: Alcoholic Iodine exhibits significant evaporation under operating room conditions after 30 minutes. Alcoholic Chlorhexidine does not appear to undergo similar losses in concentration. We recommend that alcoholic surgical preparation solutions must be poured immediately prior to use, and must be discarded if left un-covered for more than a few minutes.展开更多
Non-alcoholic steatohepatitis (NASH) can progress to cirrhosis or hepatocellular carcinoma. Oxidative stress is implicated in NASH progression. Fermented papaya preparation (FPP) has oxygen radical scavenging activity...Non-alcoholic steatohepatitis (NASH) can progress to cirrhosis or hepatocellular carcinoma. Oxidative stress is implicated in NASH progression. Fermented papaya preparation (FPP) has oxygen radical scavenging activity and is effective in oxidative stress-related diseases. We investigated the effects of FPP on NASH progression using a rat NASH model. Plasma biochemical parameters and lipid peroxidation in the liver were elevated in NASH rats. Histologically, the liver of NASH rats showed liver fibrosis, mitochondrial dysfunction and over-expression of microsomal CYP2E1. Myeloperoxidase activity and nuclear factor-kappaB activation were also markedly increased in NASH. Oral administration of FPP ameliorated these changes in NASH rats. These results suggest that FPP halts NASH progression through its anti-oxidative and antiinflammatory properties.展开更多
The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni（cod）2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or ary...The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni（cod）2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or aryIboronic acids turned out to be applicable to this catalytic system. The present method does not require the use of ligands for stabilizing the nickel catalyst in most cases or additional activators for activation of altylic alcohols.展开更多
Hydroxyapatite （HAP） nanoparticles with uniform morphologies and controllable size were synthesized successfully by molecular template hydrothermal approach. The organic alcohols including ethanol, glycol, glycerol ...Hydroxyapatite （HAP） nanoparticles with uniform morphologies and controllable size were synthesized successfully by molecular template hydrothermal approach. The organic alcohols including ethanol, glycol, glycerol and butanol were used as templates to regulate the nucleation and crystal growth. The synthesized powders were characterized by X-ray diffraction, Fourier infrared spectrum and trans- mission electron microscopy. The results showed that the obtained HAP particles were uniform rod-like crystals, and the template molecular structures had significant effect on the morphology and size of HAP particles. The template molecules with longer hydrophobic groups resulted in longer particle length and larger aspect ratio. Compared with the concentration of template molecules, the template molecular structure showed larger influence on controlling the HAP morphology and size. Furthermore, the for- mation mechanism of these rod-like HAP particles prepared by alkyl alcohol templates was discussed. Moreover, hydrothermal treatment temperature and time could be also used for controlled preparation of HAP nanoparticles.展开更多
(R)- and (S)-2-Allyl-1,3,2-dinaphtho(α,β)\dioxaborepin ((R)-2 and (S)-2) have been first prepared by the reaction of (R)-(+)- or (S)-(-)-1,1′-bi-2-naphthol and triallylborane in THF at room temperature, respectivel...(R)- and (S)-2-Allyl-1,3,2-dinaphtho(α,β)\dioxaborepin ((R)-2 and (S)-2) have been first prepared by the reaction of (R)-(+)- or (S)-(-)-1,1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively. (S)-2 and (R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2-naphthyl bis(1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of (R)-2 or (S)-2 and some aliphetic or aromatic aldehydes in CH_ 2 Cl_ 2 at -78℃ for several hours afforded β-alkylenyl alcohols in up to 84.8% ee. Among them, optically active 1\|(3,5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared展开更多
文摘A novel nitrogen‐centered radical‐induced1,2‐carbon migration reaction of allylic alcohols has been developed.This method provides easy access to a variety ofα‐quaternary‐β‐amino ketones under mild reaction conditions.The reaction has a wide substrate scope and operational simplicity.Mechanistic studies suggest that1,2‐carbon migration is induced by regioselective nitrogen‐centered radical addition to the alkene unit.?2018,Dalian Institute of Chemical Physics,Chinese Academy of Sciences.Published by Elsevier B.V.All rights reserved.
文摘Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, followed by selenoxide syn-elimination and [2,3] sigmatropic rearrangement respectively to give Z-allylic alcohols stereoselectively.
文摘Allylic alcohols react with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound bidentate sulfur palladium (0) complex to form 3-arylaldehydes or ketones in good yields.
基金supported by the National Natural Science Foundation of China (U19A2014)Sichuan University(2020SCUNL204)。
文摘A highly efficient asymmetric allylic alkylation of cyclic and acyclic carbon nucleophiles with vinyl epoxides has been developed,which exhibits good functional group compatibility,high atomic and step economy.This protocol utilizes a strategy of synergistic catalysis with a chiral N,N'-dioxide/Ni~Ⅱ complex and an achiral Pd~0 catalyst,generating a series of multisubstituted allylic alcohols with a quaternary carbon stereocenter in high yield and excellent regio-,Z/E-and enantioselectivity under mild conditions.Further transformations of the product demonstrate the potential utility of this protocol in the synthesis of allyl alcohol derivatives and natural product analogues.Experimental studies revealed that the N,N′-dioxide/metal complexes play an important role in controlling the Z/E-and enantioselectivity.The density functional theory(DFT) calculations further demonstrated that multiple C–H···π interactions between the aromatic rings of the two substrates and the amide moiety in the ligand stabilized the dominant transition state.
文摘Introduction: Surgical site infections (SSIs) remain the most common health care associated infections in the surgical population. Preoperative surgical preparation solutions containing alcohol are believed to be best at eradicating skin microorganisms. The efficacy of alcohol is concentration dependant, with a concentration of greater than 60% most bactericidal. Surgical antisepsis guidelines do not stipulate how long alcoholic preparation solutions can be left out prior to use. Method: 30 ml of Alcoholic Iodine (Iodine 1% in Alcohol 70% (v/v)) and Alcoholic Chlorhexidine (Chlorhex-idine 2% in Alcohol 70% (v/v)) were left to stand in gallipots in an operating theatre equipped with laminar flow. Sam-ples were taken at 0, 30, 60 and 120 minutes and the alcohol content was analyzed. The experiment was repeated 3 times for each time interval. Results: The Alcoholic Iodine group demonstrated significant decrease in alcohol concen-tration, from a mean of 76% (SD 3.6) to a mean of 37.7% (SD 2.9) in only 30 minutes. This effect was sustained, reaching a mean concentration of 26% (SD 2.9) alcohol at 120 minutes. The Alcoholic Chlorhexidine group did not exhibit the same degree of concentration drop, the concentration dropped marginally to 71.5% (SD 2.7) at 120 minutes from 83.4% (SD 0.4). Conclusion: Alcoholic Iodine exhibits significant evaporation under operating room conditions after 30 minutes. Alcoholic Chlorhexidine does not appear to undergo similar losses in concentration. We recommend that alcoholic surgical preparation solutions must be poured immediately prior to use, and must be discarded if left un-covered for more than a few minutes.
文摘Non-alcoholic steatohepatitis (NASH) can progress to cirrhosis or hepatocellular carcinoma. Oxidative stress is implicated in NASH progression. Fermented papaya preparation (FPP) has oxygen radical scavenging activity and is effective in oxidative stress-related diseases. We investigated the effects of FPP on NASH progression using a rat NASH model. Plasma biochemical parameters and lipid peroxidation in the liver were elevated in NASH rats. Histologically, the liver of NASH rats showed liver fibrosis, mitochondrial dysfunction and over-expression of microsomal CYP2E1. Myeloperoxidase activity and nuclear factor-kappaB activation were also markedly increased in NASH. Oral administration of FPP ameliorated these changes in NASH rats. These results suggest that FPP halts NASH progression through its anti-oxidative and antiinflammatory properties.
基金We thank the National Key Research and Development Pro- gram （No. 2016YFA0202900}, the National Natural Science Foundation of China （No. 21772217）, Science and Technology Commis- sion of Shanghai Municipality （No. 18XD1405000）, the Strategic Priority Research Program of the Chinese Academy of Sciences （No. XDB20000000）, and Shanghai Institute of Organic Chemistry （sioczz201807） for financial support.
文摘The direct coupling of allylic alcohols with arylboronic acids or their derivatives catalyzed by Ni（cod）2 in the presence of a catalytic amount of base has been developed. A wide variety of allylic substrates or aryIboronic acids turned out to be applicable to this catalytic system. The present method does not require the use of ligands for stabilizing the nickel catalyst in most cases or additional activators for activation of altylic alcohols.
基金financially supported by the National Natural Science Foundation of China(Nos.51372004,21171034 and21271040)the Shanghai Municipal Natural Science Foundation for Youths(No.12ZR144100)"Chen Guang"project(No.12CG37)supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation
文摘Hydroxyapatite （HAP） nanoparticles with uniform morphologies and controllable size were synthesized successfully by molecular template hydrothermal approach. The organic alcohols including ethanol, glycol, glycerol and butanol were used as templates to regulate the nucleation and crystal growth. The synthesized powders were characterized by X-ray diffraction, Fourier infrared spectrum and trans- mission electron microscopy. The results showed that the obtained HAP particles were uniform rod-like crystals, and the template molecular structures had significant effect on the morphology and size of HAP particles. The template molecules with longer hydrophobic groups resulted in longer particle length and larger aspect ratio. Compared with the concentration of template molecules, the template molecular structure showed larger influence on controlling the HAP morphology and size. Furthermore, the for- mation mechanism of these rod-like HAP particles prepared by alkyl alcohol templates was discussed. Moreover, hydrothermal treatment temperature and time could be also used for controlled preparation of HAP nanoparticles.
文摘(R)- and (S)-2-Allyl-1,3,2-dinaphtho(α,β)\dioxaborepin ((R)-2 and (S)-2) have been first prepared by the reaction of (R)-(+)- or (S)-(-)-1,1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively. (S)-2 and (R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2-naphthyl bis(1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of (R)-2 or (S)-2 and some aliphetic or aromatic aldehydes in CH_ 2 Cl_ 2 at -78℃ for several hours afforded β-alkylenyl alcohols in up to 84.8% ee. Among them, optically active 1\|(3,5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared
