A nickel‐catalyzed 1,4‐carbofluoroalkylation of 1,3‐enynes to access structurally diverse fluoroalkylated allenes has been established. This method has demonstrated high catalytic reactivity, mild ...reaction conditions, broad substrate scope, and excellent functional‐group tolerance. The key to success is the use of a nickel catalyst to generate different fluoroalkyl radicals from readily available and structurally diverse fluoroalkyl halides to access 1,4‐difunctionalization of 1,3‐enynes by a radical relay. This strategy provides facile synthesis of structurally diverse multisubstituted allenes, and offers a solution for batch production of various fluorinated bioactive molecules for drug discovery by further transformations.
Radical relay: A nickel‐catalyzed 1,4‐carbofluoroalkylation of 1,3‐enynes provides fluoroalkylated allenes under mild reaction conditions and with excellent functional‐group tolerance. The key to success is the use of the nickel catalyst to generate different fluoroalkyl radicals from fluoroalkyl halides to realize the 1,4‐difunctionalization by a radical relay.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Efficient difunctionalization of alkenes allows the rapid construction of molecular complexity from simple building blocks in organic synthesis. We present herein a nickel-catalyzed ...dicarbofunctionalization of alkenes using readily available organoboronic acids and organic halides in a three-component fashion. In particular, an unprecedented regioselectivity of the 1,3-dicarbofunctionalization of
-allylpyrimidin-2-amine is achieved when aryl and methyl iodides are utilized. In contrast, the use of alkyl bromides with β-hydrogens results in 1,3-hydroarylation or oxidative 1,3-diarylation. Preliminary mechanistic studies suggest an isomerization involving nickel hydride in the 1,3-difunctionalization reactions. On the other hand, the use of alkenyl or alkynyl halides promotes alternative regioselectivities to deliver 1,2-alkenylcarbonation or intriguing 2,1-alkynylcarbonation products. Such 2,1-alkynylarylation is also applicable to
-allylbenzamide as a different class of substrates. Overall, this nickel-catalyzed process proves to be powerful in delivering versatile difunctionalized compounds using readily available reagents/catalysts and a simple procedure.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Vitamin B.sub.12 is an essential vitamin that is widely used in medical and food industries. Vitamin B.sub.12 biosynthesis is confined to few bacteria and archaea, and as such its production relies ...on microbial fermentation. Rational strain engineering is dependent on efficient genetic tools and a detailed knowledge of metabolic pathways, regulation of which can be applied to improve product yield. Recent advances in synthetic biology and metabolic engineering have been used to efficiently construct many microbial chemical factories. Many published reviews have probed the vitamin B.sub.12 biosynthetic pathway. To maximize the potential of microbes for vitamin B.sub.12 production, new strategies and tools are required. In this review, we provide a comprehensive understanding of advances in the microbial production of vitamin B.sub.12, with a particular focus on establishing a heterologous host for the vitamin B.sub.12 production, as well as on strategies and tools that have been applied to increase microbial cobalamin production. Several worthy strategies employed for other products are also included.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Hydrogenation of alkenes is one of the most fundamental transformations in organic synthesis, and widely used in the petrochemical, pharmaceutical, and food industries. Although numerous ...hydrogenation methods have been developed, novel types of catalysis with new mechanisms and new hydrogen sources are still desirable. Thioxanthone (TX) is widely used in energy‐transfer photoreactions, but rarely in photoredox processes. Herein we show that a catalytic amount of TfOH as a co‐catalyst can tune the properties of TX to make it a photoredox catalyst with highly enhanced oxidative capability in the hydrogenation of carbonylated alkenes with the cheap petroleum industrial product p‐xylene serving as the hydrogen source. Deuterium can also be introduced by this method by using D2O as the D source. To the best of our knowledge, this is the first example of using p‐xylene as a hydrogen source.
A novel organic photoredox catalyst was discovered by simply adding a catalytic amount of TfOH as a co‐catalyst to readily available thioxanthone. The new catalyst, 9‐HTXTF, shows a sufficiently long singlet lifetime and adequately strong oxidation potential, as well as relatively facile photoexcitation, with applications in the hydrogenation and deuteration of carbonylated alkenes.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Monofluorinated alkyl compounds are of great importance in pharmaceuticals, agrochemicals and materials. Herein, we describe a direct nickel‐catalyzed monofluoromethylation of unactivated alkyl ...halides using a low‐cost industrial raw material, bromofluoromethane, by demonstrating a general and efficient reductive cross‐coupling of two alkyl halides. Results with 1‐bromo‐1‐fluoroalkane also demonstrate the viability of monofluoroalkylation, which further established the first example of reductive C(sp3)‐C(sp3) cross‐coupling fluoroalkylation. These transformations demonstrate high efficiency, mild conditions, and excellent functional‐group compatibility, especially for a range of pharmaceuticals and biologically active compounds. Mechanistic studies support a radical pathway. Kinetic studies reveal that the reaction is first‐order dependent on catalyst and alkyl bromide whereas the generation of monofluoroalkyl radical is not involved in the rate‐determining step. This strategy provides a general and efficient method for the synthesis of aliphatic fluorides.
A direct nickel‐catalyzed monofluoroalkylation of unactivated alkyl halides has been established, by demonstrating the first example of reductive C(sp3)−C(sp3) cross‐coupling fluoroalkylation. These transformations exhibited high efficiency, mild conditions, and excellent functional‐group compatibility, especially for a range of pharmaceuticals and biologically active compounds.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Lower respiratory tract (LRT) microbiome has been reported to associate with pulmonary diseases. Unregulated inflammation is an underlying cause of variable lung diseases. The lung microbiome may ...play an important role in the smoking-induced inflammatory lung diseases. What's more, the function of microbiome may be more important for understanding how microbes interact with host. Our study aims to explore the effects of smoking on the lower respiratory tract microbiome, the association between variation of lower respiratory tract microbiome and inflammation and whether smoking exposure changes the function of lower respiratory tract microbime.
Forty male mice were randomly divided into smoking group and non-smoking group, and the smoking group was exposed to cigarette smoke for 2 h per day for 90 days. After experiment, the blood samples were collected to measure the concentration of interleukin-6 (IL-6) and C reactive protein (CRP) by ELISA. Lung tissue samples were used to detect the community and diversity of lower respiratory tract microbiome through 16S rRNA gene quantification and sequencing technology. ANOSIM and STAMP were performed to analyze the differences of the microbial community structure between smoking group and non-smoking group. SPSS 24.0 software was used to analyze the correlations between microbiome and inflammation mediators through scatter plots and Spearman correlation coefficient. Microbial metabolic function was predicted by PICRUSt based on the 16 s rRNA gene quantification and sequencing results. PATRIC database was searched for the potential pathogenic bacteria in lower respiratory tract.
Our results suggested that smoking had markedly effects on the microbiota structure of lower respiratory tract based on Bray-Curtis distance (R
= 0.084, p = 0.005) and on unweighted uniFrac distance (R
= 0.131, p = 0.002). Smoking mainly affected the abundance of microbiome which belong to Proteobacteria phyla and Firmicutes phyla. Moreover, our results also found that smoking increased the abundance of Acinetobacter, Bacillus and Staphylococcus, which were defined as pathogenic bacteria. Inflammatory mediators were observed to associate with certain microbiome at every level. Most of microbiome which were associated with inflammation belonged to Proteobacteria phyla or Firmicutes phyla. Moreover, we found that the decreased microbiome in smoking group, including Oceanospirillales, Desulfuromonadales, Nesterenkonia, and Lactobacillaceae, all were negatively correlated with IL-6 or CRP. Based on the level of inflammation, the abundance of microbiome differs. At genus level, Lactobacillus, Pelagibacterium, Geobacter and Zoogloea were significantly higher in smoking group with lower IL-6 concentration. The abundance of microbiome was not observed any statistical difference in subgroups with different weight. Three dominant genus, defined as pathogen, were found higher in the smoking group. The microbial functional prediction analysis revealed that ABC-type transport systems, transcription factors, amino acide transport and metabolism, arginine and proline metabolism et al. were distinctively decreased in smoking group, while the proportions of replication, recombination and repair, ribosome, DNA repair and recombination proteins were increased in smoking group (q < 0.05).
Members of Proteobacteria phyla and Firmicutes phyla played an important role in the microbial community composition and keeping a relatively balanced homeostasis. Microbiome dysbiosis might break the balance of immune system to drive lung inflammation. There might exist potential probiotics in lower respiratory tract, such as Lactobacillaceae. The altered function of Lower respiratory tract microbiome under smoking exposure may affect the physiological homeostasis of host.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Monofluoroalkanes are important in many pharmaceuticals, agrochemicals and functional materials. However, the lack of easily available and transformable monofluoroalkylating reagents that facilitate ...a broad array of transformations has hampered the application of monofluoroalkylation. Herein, we report a general and efficient method of preparing diverse aliphatic monofluorides with monofluoroalkyl triflate as the synthetic scaffold. Using both nickel‐catalyzed hydromonofluoroalkylation of unactivated alkenes and copper‐catalyzed C−C bond formation, the general diversification of the monofluoroalkylating scaffold has been exhibited. The broad utility of this monofluoroalkylating reagent is shown by concise conversion into various conventional fluoroalkylating reagents and construction of monofluoro‐alkoxy, ‐alkylamino motifs with commercially available heteroatom‐based coupling partners.
A general method allows preparation of diverse monofluorides based on the monofluoroalkyl triflate scaffold. Both nickel‐catalyzed hydromonofluoroalkylation of unactivated alkenes and copper‐catalyzed monofluoroalkylation of Grignard reagents were studied. Further utilities including conversion into conventional fluoroalkylating reagents and construction of monofluoro‐alkoxy, ‐alkylamino motifs.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The truncated chromosome 22 that results from the reciprocal translocation t(9;22)(q34;q11) is known as the Phila?delphia chromosome(Ph) and is a hallmark of chronic myeloid leukemia(CML).In leukemia ...cells,Ph not only impairs the physiological signaling pathways but also disrupts genomic stability.This aberrant fusion gene encodes the breakpoint cluster region?proto?oncogene tyrosine?protein kinase(BCR?ABL1) oncogenic protein with persistently enhanced tyrosine kinase activity.The kinase activity is responsible for maintaining proliferation,inhibiting differentia?tion,and conferring resistance to cell death.During the progression of CML from the chronic phase to the accelerated phase and then to the blast phase,the expression patterns of different BCR?ABL1 transcripts vary.Each BCR?ABL1 transcript is present in a distinct leukemia phenotype,which predicts both response to therapy and clinical outcome.Besides CML,the Ph is found in acute lymphoblastic leukemia,acute myeloid leukemia,and mixed?phenotype acute leukemia.Here,we provide an overview of the clinical presentation and cellular biology of different phenotypes of Ph?positive leukemia and highlight key findings regarding leukemogenesis.
Parkinson's disease (PD) patients face a substantial unmet need for disease-modifying interventions. Potential approaches such as exercise and acupuncture have been investigated to slow PD ...progression. To address this unmet need, we developed a novel therapeutic approach that integrates acupuncture and exercise: the Meridian Activation Remedy System for PD patients (MARS-PD). Building upon promising outcomes observed in our preliminary pilot study, where MARS-PD exhibited a large clinically important difference on the Movement Disorder Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS Part III), we embark on a randomized controlled trial with the primary objective of examining the efficacy, safety, and economic impact of MARS-PD.
In this single-center, assessor and statistician-blinded, parallel-group randomized controlled trial, we aim to investigate the clinical efficacy of MARS-PD through 16 interventions administered over 8 weeks in 88 PD patients. Participants will be randomly assigned to the experimental (n = 44) or control (n = 44) groups. The experimental group will receive MARS-PD intervention alongside standard care, while the control group will solely receive standard care. The intervention period spans 8 weeks, followed by a 12-week post-intervention follow-up. The primary endpoint is the change in MDS-UPDRS Part III score from baseline to the conclusion of the 8-week intervention. Secondary outcomes encompass various assessments, including MDS-UPDRS, International Physical Activity Questionnaire Short Form, Parkinson Self Questionnaire, Parkinson's Disease Sleep Scale, Timed Up and Go test, GAITRite metrics, Functional Near-Infrared Spectroscopy measurements, smart band outcomes, gut microbiome analysis results, and iris connective tissue texture.
Previous studies by the authors have indicated MARS-PD's safety and benefits for PD patients. Building upon this foundation, our current study aims to provide a more comprehensive and detailed confirmation of the efficacy of MARS-PD.
cris.nih.go.kr KCT0006646 -First posted on 7 October 2021; ClinicalTrials.gov NCT05621772 -First posted on 11 November 2022.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
C-N bonds play a critical role in pharmaceutical, agrochemical, and materials sciences, necessitating ever-better methods to forge this linkage. Here we report a simple procedure for direct C(sp
3
...)-H azidation using iron or manganese catalysis and a nucleophilic azide source. All reagents are commercially available, the experimental procedure is simple, and we can use the C-H donor substrate as the limiting reagent, a challenge for many C-H azidation methods. Preliminary experiments are consistent with a hydrogen atom transfer (HAT)/radical ligand transfer (RLT) radical cascade mechanism and a wide variety of substrates can be azidated in moderate to high yields.
C(sp
3
)-H bonds can be directly azidated using simple iron and manganese catalysts and commercial Selectfluor and TMSN
3
as reagents.
PDF
