scholarly journals 1,3,4-Oxadiazole and Heteroaromatic-Fused 1,2,4-Triazole Synthesis­ Using Diverted Umpolung Amide Synthesis

Synthesis ◽  
2017 ◽  
Vol 49 (20) ◽  
pp. 4670-4675 ◽  
Author(s):  
Kazuyuki Tokumaru ◽  
Kalisankar Bera ◽  
Jeffrey Johnston
Keyword(s):  
Synthesis Methods ◽  
Tetrahedral Intermediate ◽  
Amide Synthesis ◽  
Direct Pathway

Umpolung Amide Synthesis (UmAS) has emerged as a superior alternative to conventional amide synthesis methods based on carbonyl electrophiles in a range of situations, particularly when epimerization-prone couplings are prescribed. In an unanticipated development during our most recent studies, we discovered that diacyl hydrazide products from UmAS were not formed as intermediates when using an acyl hydrazide as the amine acceptor. This resulted in a new preparation of 1,3,4-oxadiazoles from α-bromonitroalkane donors. We hypothesized that a key tetrahedral intermediate in UmAS was diverted toward a more direct pathway to the heterocycle product rather than through formation of the diacyl hydrazide, a typical oxadiazole progenitor. In studies reported here, diversion to 1,2,4-triazole products is described, a behavior hypothesized to also result from an analogous tetrahedral intermediate, but one formed from heteroaromatic hydrazine acceptors.

Hotspots in Psychology – 2020 Edition

2020 ◽  
Vol 228 (1) ◽  
pp. 1-2
Author(s):  
Michael Bošnjak ◽  
Nadine Wedderhoff
Keyword(s):  
Systematic Reviews ◽  
Research Synthesis ◽  
Synthesis Methods ◽  
Common Denominator ◽  
The Common ◽  
Meta Analyses

Abstract. This editorial gives a brief introduction to the six articles included in the fourth “Hotspots in Psychology” of the Zeitschrift für Psychologie. The format is devoted to systematic reviews and meta-analyses in research-active fields that have generated a considerable number of primary studies. The common denominator is the research synthesis nature of the included articles, and not a specific psychological topic or theme that all articles have to address. Moreover, methodological advances in research synthesis methods relevant for any subfield of psychology are being addressed. Comprehensive supplemental material to the articles can be found in PsychArchives ( https://www.psycharchives.org ).

Effects of Wet Chemical Oxidation on Surface Functionalization and Morphology of Highly Oriented Pyrolytic Graphite

2020 ◽  
Author(s):  
Mikhail Trought ◽  
Isobel Wentworth ◽  
Timothy Leftwich ◽  
Kathryn Perrine
Keyword(s):  
Surface Functionalization ◽  
Functional Group ◽  
Pyrolytic Graphite ◽  
Surface Oxidation ◽  
Chemical Oxidation ◽  
Synthesis Methods ◽  
Acid Solutions ◽  
Highly Oriented Pyrolytic Graphite ◽  
Wet Chemical ◽  
Surface Morphologies

The knowledge of chemical functionalization for area selective deposition (ASD) is crucial for designing the next generation heterogeneous catalysis. Surface functionalization by oxidation was studied on the surface of highly oriented pyrolytic graphite (HOPG). The HOPG surface was exposed to with various concentrations of two different acids (HCl and HNO3). We show that exposure of the HOPG surface to the acid solutions produce primarily the same -OH functional group and also significant differences the surface topography. Mechanisms are suggested to explain these strikingly different surface morphologies after surface oxidation. This knowledge can be used to for ASD synthesis methods for future graphene-based technologies.

Nested code sequences of Barker — Mersenne — Raghavarao

2019 ◽  
pp. 71-81
Author(s):  
M. B. Sergeev ◽  
V. A. Nenashev ◽  
A. M. Sergeev
Keyword(s):  
Data Transfer ◽  
Radio Channel ◽  
Main Peak ◽  
Synthesis Methods ◽  
Orthogonal Matrices ◽  
Useful Signal ◽  
New Codes ◽  
Increase In Accuracy ◽  
Application Fields ◽  
Barker Codes

Introduction: The problem of noise-free encoding for an open radio channel is of great importance for data transfer. The results presented in this paper are aimed at stimulating scientific interest in new codes and bases derived from quasi-orthogonal matrices, as a basis for the revision of signal processing algorithms.Purpose: Search for new code sequences as combinations of codes formed from the rows of Mersenne and Raghavarao quasi-orthogonal matrices, as well as complex and more efficient Barker — Mersenne — Raghavarao codes.Results: We studied nested code sequences derived from the rows of quasi-orthogonal cyclic matrices of Mersenne, Raghavarao and Hadamard, providing estimates for the characteristics of the autocorrelation function of nested Barker, Mersenne and Raghavarao codes, and their combinations: in particular, the ratio between the main peak and the maximum positive and negative “side lobes”. We have synthesized new codes, including nested ones, formed on the basis of quasi-orthogonal matrices with better characteristics than the known Barker codes and their nested constructions. The results are significant, as this research influences the establishment and development of methods for isolation, detection and processing of useful information. The results of the work have a long aftermath because new original code synthesis methods need to be studied, modified, generalized and expanded for new application fields.Practical relevance: The practical application of the obtained results guarantees an increase in accuracy of location systems, and detection of a useful signal in noisy background. In particular, these results can be used in radar systems with high distance resolution, when detecting physical objects, including hidden ones.

Metallic Nanoparticle Synthesis by Green Chemistry

2018 ◽  
Vol 11 (6) ◽  
pp. 4287-4294
Author(s):  
Anikate Sood ◽  
Shweta Agarwal
Keyword(s):  
Green Chemistry ◽  
Green Synthesis ◽  
Biomedical Research ◽  
Metallic Nanoparticles ◽  
Nanoparticle Synthesis ◽  
Synthesis Methods ◽  
Metallic Nanoparticle ◽  
Medical Field ◽  
Advantages And Disadvantages ◽  
Gold Silver

Nanotechnology is the most sought field in biomedical research. Metallic nanoparticles have wide applications in the medical field and have gained the attention of various researchers for advanced research for their application in pharmaceutical field. A variety of metallic nanoparticles like gold, silver, platinum, palladium, copper and zinc have been developed so far. There are different methods to synthesize metallic nanoparticles like chemical, physical, and green synthesis methods. Chemical and physical approaches suffer from certain drawbacks whereas green synthesis is emerging as a nontoxic and eco-friendly approach in production of metallic nanoparticles. Green synthesis is further divided into different approaches like synthesis via bacteria, fungi, algae, and plants. These approaches have their own advantages and disadvantages. In this article, we have described various metallic nanoparticles, different modes of green synthesis and brief description about different metabolites present in plant that act as reducing agents in green synthesis of metallic nanoparticles. 

SYNTHESIS METHODS OF OPTIMAL DISCRETE CORRECTIVE FUNCTIONS

2020 ◽  
Vol 9 (9) ◽  
pp. 6467-6482
Author(s):  
A.V Kabulov ◽  
E. Urunbaev ◽  
I. Normatov ◽  
A. Ashurov
Keyword(s):  
Synthesis Methods

Green Synthesized Nanomaterials as Theranostic Platforms for Cancer Treatment: Principles, Challenges and the Road Ahead

2019 ◽  
Vol 26 (8) ◽  
pp. 1311-1327 ◽  
Author(s):  
Pala Rajasekharreddy ◽  
Chao Huang ◽  
Siddhardha Busi ◽  
Jobina Rajkumari ◽  
Ming-Hong Tai ◽  
...  
Keyword(s):  
Nanoparticle Synthesis ◽  
Research Field ◽  
Synthesis Methods ◽  
Synthetic Approach ◽  
Future Directions ◽  
The Road ◽  
New Methods ◽  
Recent Developments ◽  
Theranostic Applications ◽  
Insight Into

With the emergence of nanotechnology, new methods have been developed for engineering various nanoparticles for biomedical applications. Nanotheranostics is a burgeoning research field with tremendous prospects for the improvement of diagnosis and treatment of various cancers. However, the development of biocompatible and efficient drug/gene delivery theranostic systems still remains a challenge. Green synthetic approach of nanoparticles with low capital and operating expenses, reduced environmental pollution and better biocompatibility and stability is a latest and novel field, which is advantageous over chemical or physical nanoparticle synthesis methods. In this article, we summarize the recent research progresses related to green synthesized nanoparticles for cancer theranostic applications, and we also conclude with a look at the current challenges and insight into the future directions based on recent developments in these areas.

Advances in the Initiation System and Synthesis Methods of Cationic Poly-acrylamide: A Review

2016 ◽  
Vol 13 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Chuanliang Zhao ◽  
Huaili Zheng ◽  
Yuxin Zhang ◽  
Jinsong Guo ◽  
Yongjun Sun ◽  
...  
Keyword(s):  
Synthesis Methods ◽  
Initiation System ◽  
Poly Acrylamide
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