scholarly journals Palladium-catalyzed enantioselective carbonylation reactions

Author(s):  
Jin-Bao Peng ◽  
Xin-Lian Liu ◽  
Lin Li ◽  
Xiao-Feng Wu

AbstractCarbonylation, one of the most powerful approaches to the preparation of carbonylated compounds, has received significant attention from researchers active in various fields. Indeed, impressive progress has been made on this subject over the past few decades. Among the various types of carbonylation reactions, asymmetric carbonylation is a straightforward methodology for constructing chiral compounds. Although rhodium-catalyzed enantioselective hydroformylations have been discussed in several elegant reviews, a general review on palladium-catalyzed asymmetric carbonylations is still missing. In this review, we summarize and discuss recent achievements in palladium-catalyzed asymmetric carbonylation reactions. Notably, this review’s contents are categorized by reaction type.

2020 ◽  
Vol 23 (8) ◽  
pp. 687-698 ◽  
Author(s):  
Houda N. Washah ◽  
Elliasu Y. Salifu ◽  
Opeyemi Soremekun ◽  
Ahmed A. Elrashedy ◽  
Geraldene Munsamy ◽  
...  

For the past few decades, the mechanisms of immune responses to cancer have been exploited extensively and significant attention has been given into utilizing the therapeutic potential of the immune system. Cancer immunotherapy has been established as a promising innovative treatment for many forms of cancer. Immunotherapy has gained its prominence through various strategies, including cancer vaccines, monoclonal antibodies (mAbs), adoptive T cell cancer therapy, and immune checkpoint therapy. However, the full potential of cancer immunotherapy is yet to be attained. Recent studies have identified the use of bioinformatics tools as a viable option to help transform the treatment paradigm of several tumors by providing a therapeutically efficient method of cataloging, predicting and selecting immunotherapeutic targets, which are known bottlenecks in the application of immunotherapy. Herein, we gave an insightful overview of the types of immunotherapy techniques used currently, their mechanisms of action, and discussed some bioinformatics tools and databases applied in the immunotherapy of cancer. This review also provides some future perspectives in the use of bioinformatics tools for immunotherapy.


Synthesis ◽  
2020 ◽  
Author(s):  
Lili Shi ◽  
Junkai Fu ◽  
Shuangqiu Gao ◽  
Le Chang ◽  
Binglin Wang

AbstractThe Mizoroki–Heck reaction is considered as one of the most ingenious and widely used methods for constructing C–C bonds. This reaction mainly focuses on activated olefins (styrenes, acrylates, or vinyl ethers) and aryl/vinyl (pseudo) halides. In comparison, the studies on unactivated alkenes and alkyl electrophiles are far less due to the low reactivity, poor selectivity, as well as competitive β-H elimination. In the past years, a growing interest has thus been devoted and significant breakthroughs have been achieved in the employment of unactivated alkenes and alkyl electrophiles as the reaction components, and this type of coupling is called as Heck-type or Heck-like reaction, which distinguishes from the traditional Heck reaction. Herein, we give a brief summary on Heck-type reaction between unactivated alkenes and alkyl electrophlies, covering its initial work, recent advancements, and mechanistic discussions.1 Introduction2 Intramolecular Heck-Type Reaction of Unactivated Alkenes and Alkyl Electrophiles2.1 Cobalt-Catalyzed Intramolecular Heck-Type Reaction2.2 Palladium-Catalyzed Intramolecular Heck-Type Reaction2.3 Nickel-Catalyzed Intramolecular Heck-Type Reaction2.4 Photocatalysis and Multimetallic Protocol for Intramolecular Heck-Type Reaction3 Intermolecular Heck-Type Reaction of Unactivated Alkenes and Alkyl Electrophiles3.1 Electrophilic Trifluoromethylating Reagent as Reaction Partners3.2 Alkyl Electrophiles as Reaction Partners4 Oxidative Heck-Type Reaction of Unactivated Alkenes and Alkyl Radicals5 Conclusions and Outlook


2012 ◽  
Vol 40 (4) ◽  
pp. 990-996 ◽  
Author(s):  
Ryan Spellecy ◽  
Thomas May

Deception, cheating, and loopholes within the IRB approval process have received significant attention in the past several years. Surveys of clinical researchers indicate common deception ranging from omitting information to outright lying, and controversy surrounding the FDA's decision not to ban “IRB shopping” (the practice of submitting protocols to multiple IRBs until one is found that will approve the protocol) has raised legitimate concerns about the integrity of the IRB process. One author has described a multicenter trial as being withdrawn from consideration at one institution when rejection was imminent, in order to avoid informing other IRBs reviewing the protocol of the study's rejection (a requirement under the federal regulations for emergency research with an exception from informed consent). This practice and IRB shopping seem at odds with the spirit, if not the “letter,” of the regulations. While at first blush these practices seem to cast aspersions on the integrity of clinical researchers, the moral issues raised go deeper than the ethics of cheating.


2015 ◽  
Vol 44 (11) ◽  
pp. 3418-3430 ◽  
Author(s):  
J. Wencel-Delord ◽  
A. Panossian ◽  
F. R. Leroux ◽  
F. Colobert

Over the past decade the field of the synthesis of axially chiral compounds has been rapidly expanding. Not only key advances have been achieved concerning the already established strategies but also new synthetic routes have been devised. This review showcases the recent developments in this domain.


2019 ◽  
Vol 11 (2) ◽  
pp. 31 ◽  
Author(s):  
Naser Ojaroudi Parchin ◽  
Haleh Jahanbakhsh Basherlou ◽  
Raed Abd-Alhameed ◽  
James Noras

Over the past decade, radio-frequency identification (RFID) technology has attracted significant attention and become very popular in different applications, such as identification, management, and monitoring. In this study, a dual-band microstrip-fed monopole antenna has been introduced for RFID applications. The antenna is designed to work at the frequency ranges of 2.2–2.6 GHz and 5.3–6.8 GHz, covering 2.4/5.8 GHz RFID operation bands. The antenna structure is like a modified F-shaped radiator. It is printed on an FR-4 dielectric with an overall size of 38 × 45 × 1.6 mm3. Fundamental characteristics of the antenna in terms of return loss, Smith Chart, phase, radiation pattern, and antenna gain are investigated and good results are obtained. Simulations have been carried out using computer simulation technology (CST) software. A prototype of the antenna was fabricated and its characteristics were measured. The measured results show good agreement with simulations. The structure of the antenna is planar, simple to design and fabricate, easy to integrate with RF circuit, and suitable for use in RFID systems.


2000 ◽  
Vol 6 (S2) ◽  
pp. 530-531
Author(s):  
M.G. Burke ◽  
P.T. Duda ◽  
G. Botton ◽  
M. W. Phaneuf

Focused Ion Beam (FIB) micromachining techniques have gained significant attention over the past few years as a promising method for the preparation of a variety of metallic and nonmetallic materials for subsequent characterization using transmission electron microscopy (TEM) The advantage of the FIB in terms of site specificity and speed for the preparation of uniform electron transparent sections has opened a wide range of potential applications in materials characterization. The ability to image the sample in the FIB can also provide important microstructural data for materials analysis. In this study, both conventionally electropolished and FIB-ed specimens were prepared in order to characterize the microstructure of a commercially-produced tube of Alloy 600 (approximately Ni-15 Cr-10 Fe- 0.05 C). The electropolished samples were prepared using a solution of 20% HClO4 - 80% CH3OH at ∼-40°C. The FIB sections were obtained from a cross-section of the tube that had been mechanically thinned to ∼100 μm. The section was thinned in a Micrion 2500 FIB system with a Ga ion beam at 50 kV accelerating voltage.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4906
Author(s):  
Jurriën W. Collet ◽  
Thomas R. Roose ◽  
Bram Weijers ◽  
Bert U. W. Maes ◽  
Eelco Ruijter ◽  
...  

Isocyanides have long been known as versatile chemical reagents in organic synthesis. Their ambivalent nature also allows them to function as a CO-substitute in palladium-catalyzed cross couplings. Over the past decades, isocyanides have emerged as practical and versatile C1 building blocks, whose inherent N-substitution allows for the rapid incorporation of nitrogeneous fragments in a wide variety of products. Recent developments in palladium catalyzed isocyanide insertion reactions have significantly expanded the scope and applicability of these imidoylative cross-couplings. This review highlights the advances made in this field over the past eight years.


2017 ◽  
Vol 47 (2) ◽  
pp. 121-134
Author(s):  
Carlin J Miller ◽  
Emily-Ann Di Pierdomenico ◽  
Marta Kadziolka

Mindfulness has received significant attention in the empirical literature during the past decade, but few studies have focused on mindfulness in university students and how it may influence problematic behaviours. This study examined the relationships among mindfulness, coping, and physiological reactivity in a sample of university students. Participants completed questionnaires, and skin conductance measurements were collected during an interview where they recalled a personally stressful event. Correlation analyses tested relationships among these variables. There was a negative correlation between substance use and mindfulness. Specifically, those using substances as a coping mechanism were less likely to be mindful and displayed higher physiological reactivity. More mindful individuals were less likely to report misusing substances and were able to calm themselves more quickly than their counterparts following a stressful event. Thus, poor outcomes for distressed students may be reduced with mindfulness-based interventions.  


2020 ◽  
Vol 8 (16) ◽  
pp. 4559-4569
Author(s):  
Jue-Ping Feng ◽  
Ru Zhu ◽  
Fagang Jiang ◽  
Jie Xie ◽  
Chang Gao ◽  
...  

Anticancer peptides (ACPs) have gained significant attention in the past few years.


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