Zr‐MOF‐808 as Catalyst for Amide Esterification Villoria‐del‐Álamo, Beatriz; Rojas‐Buzo, Sergio; García‐García, Pilar ...
Chemistry,
March 8, 2021, Letnik:
27, Številka:
14
Journal Article
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In this work, zirconium‐based metal–organic framework Zr‐MOF‐808‐P has been found to be an efficient and versatile catalyst for amide esterification. Comparing with previously reported homogeneous ...and heterogeneous catalysts, Zr‐MOF‐808‐P can promote the reaction for a wide range of primary, secondary and tertiary amides with n‐butanol as nucleophilic agent. Different alcohols have been employed in amide esterification with quantitative yields. Moreover, the catalyst acts as a heterogeneous catalyst and could be reused for at least five consecutive cycles. The amide esterification mechanism has been studied on the Zr‐MOF‐808 at molecular level by in situ FTIR spectroscopic technique and kinetic study.
Zr‐MOF‐808‐P is shown as an efficient reusable heterogeneous catalyst for amide esterification with ample substrate scope. The reaction mechanism is studied by in situ FTIR spectroscopy.
Room to swing a cat: A chiral disulfonimide has been designed as a powerful new motif for asymmetric catalysis. As a first illustration, a highly efficient and enantioselective Mukaiyama aldol ...reaction has been developed (see scheme). The actual catalyst is proposed to be an N-silyl imide which is generated in situ.
Counteranion control enables the enantioselective, organo Lewis acid catalyzed Hosomi–Sakurai reaction of (hetero)aromatic aldehydes and allylsilanes using an easily handled disulfonimide precatalyst ...(see scheme). The key to the success of this system is to turn the usually undesired silylium ion catalysis into the desired catalytic regime and pair the cation with an enantiopure disulfonimide anion, thereby applying the concept of asymmetric counteranion‐directed catalysis.
Among the large family of metal‐organic frameworks (MOFs), Hf‐based MOFs are foreseen as promising materials for practical applications due to their exceptional characteristics such as rich structure ...versatility and outstanding stability. This review discusses catalytic applications of Hf‐MOFs since their development in 2012, and are summarized according to the location of the active site: at the hafnium node, at the linker or as a single‐site chemical entity located at the hafnium node after post‐synthetic functionalization. Special emphasis is made to synthetic preparation methods and catalytic performance.
Let's talk about six! A new chiral disulfonimide catalyzed vinylogous Mukaiyama aldol addition of crotonic acid derived nucleophiles to aldehydes has been developed and the concept of vinylogy was ...further expanded to double vinylogous, sorbic acid derived nucleophiles. This reaction is an example of a previously unknown ε‐selective bisvinylogous Mukaiyama Aldol addition that extends the substrate by six carbon atoms (see scheme).
Multisite organic–inorganic hybrid catalysts have been prepared and applied in a new general, practical, and sustainable synthetic procedure toward industrially relevant GABA derivatives. The domino ...sequence is composed of seven chemical transformations which are performed in two one‐pot reactions. The method produces both enantiomeric forms of the product in high enantiopurity as well as the racemate in good yields after a single column purification step. This protocol highlights major process intensification, catalyst recyclability, and low waste generation.
Seven steps in two pots: Organic–inorganic hybrid catalysts have been prepared and applied in a new general, practical, and flexible synthetic procedure toward industrially relevant GABA derivatives. The domino sequence is composed of seven chemical transformations which are performed in two one‐pot reactions. The method produces both enantiomeric forms of the product in high enantiopurity as well as the racemate in good yields.
Religious leaders have the potential to play a significant role in the identification and referral of individuals with mental health problems.
This study sought to understand the perceptions of ...religious leaders in regards to identifying and referring parishioners with mental health issues to healthcare professionals, in Chimbote, Peru.
We performed a cross-sectional study that covered religious leaders of different religious groups in Chimbote. The leaders completed a survey that assessed their characteristics, past experiences of detecting and referring those with mental health problems to healthcare professionals, and perceptions of four clinical cases (for which we used the Clergy's Perception of Mental Illness Survey instrument).
We included 109 religious' leaders of four religious groups (11 Catholics, 70 Evangelicals, 21 Mormons, and 7 Adventists). Of these, 50.5% had received at least one request for help with mental health issues from a parishioner in the previous month, over 85% expressed a desire for training in identifying mental health problems, and 22-30% reported receiving any training. While the majority of leaders were able to correctly identify cases of depression, alcohol dependence, and drug problems, only 62% correctly classified a case of schizophrenia. Despite this, 80% stated that they would refer their parishioners to healthcare professionals.
Parishioners tend to consult their religious leaders regarding their mental health and approximately 80% stated they would refer such cases to a healthcare professional. However, less than one-third of the leaders had received training to detect mental health problems. These results suggest that there is a need for training programs to improve the ability of religious leaders to identify and refer individuals with mental health issues.
Human neuroimaging studies have consistently reported changes in cerebellar function and integrity in association with obesity. To date, however, the nature of this link has not been studied ...directly. Emerging evidence suggests a role for the cerebellum in higher cognitive functions through reciprocal connections with the prefrontal cortex. The purpose of this exploratory study was to examine appetite changes associated with noninvasive prefronto-cerebellar neuromodulation in obesity. Totally, 12 subjects with class I obesity (mean body mass index 32.9 kg/m
) underwent a randomized, single-blinded, sham-controlled, crossover study, during which they received transcranial direct current stimulation ((tDCS); active/sham) aimed at simultaneously enhancing the activity of the prefrontal cortex and decreasing the activity of the cerebellum. Changes in appetite (state and food-cue-triggered) and performance in a food-modified working memory task were evaluated. We found that active tDCS caused an increase in hunger and desire to eat following food-cue exposure. In line with these data, subjects also tended to make more errors during the working memory task. No changes in basic motor performance occurred. This study represents the first demonstration that prefronto-cerebellar neuromodulation can influence appetite in individuals with obesity. While preliminary, our findings support a potential role for prefronto-cerebellar pathways in the behavioral manifestations of obesity.
Summary
Endophytes contribute to plant performance, especially under harsh conditions. We therefore hypothesized that wild plants have retained beneficial endophytes that are less abundant or not ...present in related crop plants. To test this hypothesis, we selected two endophytes that were found in Sharon goatgrass, an ancestor of wheat, and tested their effect on bread wheat. Both endophytes infected wheat and improved sustainability and performance under water‐limited conditions. To determine how the endophytes modify plant development, we measured parameters of plant growth and physiological status and performed a comparative metabolomics analysis. Endophyte‐treated wheat plants had reduced levels of stress damage markers and reduced accumulation of stress‐adaptation metabolites. Metabolomics profiling revealed significant differences in the response to water stress of endophyte‐treated plants compared with untreated plants. Our results demonstrate the potential of endophytes from wild plants for improvement of related crops and show that the beneficial effects of two endophytes are associated with alteration of physiological responses to water‐limited conditions.
Background
The measurement of myocardial deformation by strain analysis is an evolving tool to quantify regional and global myocardial function.
Purpose
To assess the feasibility and reproducibility ...of myocardial strain/strain rate measurements with magnetic resonance feature tracking (MR‐FT) in healthy subjects and in patient groups.
Study Type
Prospective study.
Population
Sixty patients (20 hypertensives with left ventricular (LV) hypertrophy (H); 20 nonischemic dilated cardiomyopathy (D); 20 ischemic heart disease (I); as well as 20 controls (C) were included, 10 men and 10 women in each group.
Field Strength/Sequence
A 1.5T MR protocol including steady‐state free precession (SSFP) cine sequences in the standard views and late enhancement sequences.
Assessment
LV volumes, mass, global and regional radial, circumferential, and longitudinal strain/strain rate were measured using CVI42 software. The analysis time was recorded.
Statistical Tests
Intraobserver and interobserver agreement and intraclass correlation coefficients (ICC) were obtained for reproducibility assessment as well as differences according to gender and group of pertinence.
Results
Strain/strain rate analysis could be achieved in all subjects. The average analysis time was 14 ± 3 minutes. The average intraobserver ICC was excellent (ICC >0.90) for strain and good (ICC >0.75) for strain rate. Reproducibility of strain measurements was good to excellent (ICC >0.75) for all groups of subjects and both genders. Reproducibility of strain measurements was good for basal segments (ICC >0.75) and excellent for middle and apical segments (ICC >0.90). Reproducibility of strain rate measurements was moderate for basal segments (ICC >0.50) and good for middle and apical segments.
Data Conclusion
MR‐FT for strain/strain rate analysis is a feasible and highly reproducible technique. CVI42 FT analysis was equally feasible and reproducible in various pathologies and between genders. Better reproducibility was seen globally for middle and apical segments, which needs further clarification.
Level of Evidence: 3
Technical Efficacy Stage 2
J. Magn. Reson. Imaging 2018;47:1415–1425.
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