scholarly journals Anomeric stereoauxiliary strategy enables efficient synthesis of wide-ranging imidazo[1,5-α]pyridines

2021 ◽  
Author(s):  
Kui Zeng ◽  
Jin Ye ◽  
Xintong Meng ◽  
Sebastian Dechert ◽  
Martin Simon ◽  
...  
Keyword(s):  
Heterocyclic Compounds ◽  
State Of The Art ◽  
Biomass Conversion ◽  
Synthetic Approach ◽  
Efficient Synthesis ◽  
The Past ◽  
Tremendous Progress ◽  
First Time ◽  
Structure Calculations ◽  
Ring Transition State

Abstract Imidazo[1,5-α]pyridines are one of the most important groups of N-heterocyclic compounds, with wide applications in pharmaceutics, chemical science and material science. Despite tremendous progress in their synthesis over the past decade, a number of important imidazo[1,5-α]pyridines as intermediate products remain inaccessible, such as 1-alkylimidazo[1,5-α]pyridines. Herein, we report a novel anomeric stereoauxiliary approach for the preparation of this important class of compounds. It strongly expands the scope of readily accessible imidazo[1,5-α]pyridines well beyond the existing state-of-the-art methods. More than 80 products with a substantial number of deemed unattainable ones were synthesized. With the first time accessibility to alkyl(pyridine-2-yl)methanone substrates, a group of important deuterated imidazo[1,5-α]pyridines derivatives were also efficiently achieved. The mechanism containing a key seven-membered ring transition state via α-anomeric stereoauxiliary for this new synthetic pathway is provided in great detail and supported by electronic structure calculations. In total, this novel synthetic approach for a broad range of imidazo[1,5-α]pyridines involving the native stereochemistry will open a new window for research endeavors in diverse fields, encompassing organic synthesis, biomass conversion via cleavage of C-N bonds and medicinal chemistry.

scholarly journals Design Space of Flexible Multigigabit LDPC Decoders

VLSI Design ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Philipp Schläfer ◽  
Christian Weis ◽  
Norbert Wehn ◽  
Matthias Alles
Keyword(s):  
Design Space ◽  
State Of The Art ◽  
Cmos Technology ◽  
Systematic Investigation ◽  
Design Parameters ◽  
Ldpc Decoder ◽  
The Past ◽  
Ieee 802.11Ad ◽  
Decoder Design ◽  
First Time

Multigigabit LDPC decoders are demanded by standards like IEEE 802.15.3c and IEEE 802.11ad. To achieve the high throughput while supporting the needed flexibility, sophisticated architectures are mandatory. This paper comprehensively presents the design space for flexible multigigabit LDPC applications for the first time. The influence of various design parameters on the hardware is investigated in depth. Two new decoder architectures in a 65 nm CMOS technology are presented to further explore the design space. In the past, the memory domination was the bottleneck for throughputs of up to 1 Gbit/s. Our systematic investigation of column- versus row-based partially parallel decoders shows that this is no more a bottleneck for multigigabit architectures. The evolutionary progress in flexible multigigabit LDPC decoder design is highlighted in an extensive comparison of state-of-the-art decoders.

OTHER SHUKSHIN: NOTES ON CONTEMPORARY STUDIES OF SHUKSHIN’S WORKS

2020 ◽  
Vol 10 (2) ◽  
pp. 39-52
Author(s):  
A.I. Kulyapin ◽  
Keyword(s):  
Doctoral Degree ◽  
Synthetic Approach ◽  
Historical Time ◽  
Holistic Model ◽  
The Past ◽  
90Th Anniversary ◽  
Scientific Significance ◽  
Political Essays ◽  
Film Making ◽  
First Time

The article is devoted to the review of monographs on the work of V.M. Shukshin, published over the past five years. Researchers of the creative heritage of the writer and film director managed to offer new prospects in the study of his works. In the monograph by D.V. Maryin, “The non-artistic work of V.M. Shukshin,” for the first time, letters, documentary autobiographies, draft notes, and social and political essays of the writer were systematically studied. The scientific significance of the research by Altai philologists “Semiotics of the artistic space of V.M. Shukshin” and “Geopoetics of V.M. Shukshin” consists in attempts to describe a holistic model of the writer’s artistic world. A book by I.V. Shestakova, “The artistic and visual principles of cinema by V.M. Shukshin,” is distinguished by a synthetic approach to Shukshin’s creativity. According to the author of this work, Shukshin’s film making is a single space for the interaction of literary, pictorial, and musical forms of arts. In addition to film critics, historians, philosophers and sociologists actively joined in the work on Shukshin’s works. The textbook by Prof. S.I. Grigoriev, (Post-Doctoral degree in Sociology) has run through several editions. S.V. Tsyb, Barnaul historian, had published his book entitled “V.M. Shukshin and historical time” by the 90th anniversary of Shukshin.

scholarly journals Pharmacogenomics of antidepressant treatment effects

2011 ◽  
Vol 13 (1) ◽  
pp. 63-71 ◽  
Keyword(s):  
Drug Discovery ◽  
Major Depression ◽  
Critical Appraisal ◽  
State Of The Art ◽  
Antidepressant Treatment ◽  
Clinical Applications ◽  
The Past ◽  
Body Of Knowledge ◽  
Tremendous Progress ◽  
Novel Targets

There has been considerable promise and hope that pharmacogenomics will optimize existing treatments for major depression, as well as identify novel targets for drug discovery. Immediately after the sequencing of the human genome, there was much hope that tremendous progress in pharmacogenomics would rapidly be achieved. In the past 10 years this initial enthusiasm has been replaced by a more sober optimism, as we have gone a long way towards the goal of guiding therapeutics based on genomics. While the effort to translate discovery to clinical applications is ongoing, we now have a vast body of knowledge as well as a clear direction forward. This article will provide a critical appraisal of the state of the art in the pharmacogenomics of depression, both in terms of pharmacodynamics and pharmacokinetics.

scholarly journals Improving the Speed of MRI with Artificial Intelligence

2020 ◽  
Vol 24 (01) ◽  
pp. 012-020 ◽  
Author(s):  
Patricia M. Johnson ◽  
Michael P. Recht ◽  
Florian Knoll
Keyword(s):  
Artificial Intelligence ◽  
State Of The Art ◽  
Future Perspectives ◽  
Resonance Imaging ◽  
The Past ◽  
Tremendous Progress ◽  
Accelerated Mri ◽  
Magnetic Resonance Imaging Mri ◽  
Image Modality ◽  
Resolution Data

AbstractMagnetic resonance imaging (MRI) is a leading image modality for the assessment of musculoskeletal (MSK) injuries and disorders. A significant drawback, however, is the lengthy data acquisition. This issue has motivated the development of methods to improve the speed of MRI. The field of artificial intelligence (AI) for accelerated MRI, although in its infancy, has seen tremendous progress over the past 3 years. Promising approaches include deep learning methods for reconstructing undersampled MRI data and generating high-resolution from low-resolution data. Preliminary studies show the promise of the variational network, a state-of-the-art technique, to generalize to many different anatomical regions and achieve comparable diagnostic accuracy as conventional methods. This article discusses the state-of-the-art methods, considerations for clinical applicability, followed by future perspectives for the field.

A Macintosh Interface for the Cameca Camebax-Micro Electron Microprobe

1990 ◽  
Vol 48 (1) ◽  
pp. 438-439
Author(s):  
Carl E. Henderson
Keyword(s):  
Electron Microprobe ◽  
Processing Speed ◽  
Word Processing ◽  
State Of The Art ◽  
Computer Control ◽  
Third Party ◽  
Disk Storage ◽  
The Past ◽  
User Facility ◽  
Instrument Control

Over the past few years it has become apparent in our multi-user facility that the computer system and software supplied in 1985 with our CAMECA CAMEBAX-MICRO electron microprobe analyzer has the greatest potential for improvement and updating of any component of the instrument. While the standard CAMECA software running on a DEC PDP-11/23+ computer under the RSX-11M operating system can perform almost any task required of the instrument, the commands are not always intuitive and can be difficult to remember for the casual user (of which our laboratory has many). Given the widespread and growing use of other microcomputers (such as PC’s and Macintoshes) by users of the microprobe, the PDP has become the “oddball” and has also fallen behind the state-of-the-art in terms of processing speed and disk storage capabilities. Upgrade paths within products available from DEC are considered to be too expensive for the benefits received. After using a Macintosh for other tasks in the laboratory, such as instrument use and billing records, word processing, and graphics display, its unique and “friendly” user interface suggested an easier-to-use system for computer control of the electron microprobe automation. Specifically a Macintosh IIx was chosen for its capacity for third-party add-on cards used in instrument control.

New Insights into the Nature of the Band Gap of CuGeO3 Nanoparticles: Synthesis, Electronic Structure, and Optical and Photocatalytic Properties

2019 ◽  
Author(s):  
Victor Y. Suzuki ◽  
Luís Henrique Cardozo Amorin ◽  
Natália H. de Paula ◽  
Anderson R. Albuquerque ◽  
Julio Ricardo Sambrano ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Gap ◽  
Material Design ◽  
Photocatalytic Properties ◽  
Critical Parameters ◽  
Synthetic Approach ◽  
Microwave Assisted ◽  
Theoretical Approaches ◽  
Nanoparticles Synthesis ◽  
First Time

<p>We report, for the first time, new insights into the nature of the band gap of <a>CuGeO<sub>3</sub> </a>(CGO) nanocrystals synthesized from a microwave-assisted hydrothermal method in the presence of citrate. To the best of our knowledge, this synthetic approach has the shortest reaction time and it works at the lowest temperatures reported in the literature for the preparation of these materials. The influence of the surfactant on the structural, electronic, optical, and photocatalytic properties of CGO nanocrystals is discussed by a combination of experimental and theoretical approaches, and that results elucidates the nature of the band gap of synthetized CGO nanocrystals. We believe that this particular strategy is one of the most critical parameters for the development of innovative applications and that result could shed some light on the emerging material design with entirely new properties.</p> <p><b> </b></p>

The Medicinal Chemistry of Therapeutic Peptides: Recent Developments in Synthesis and Design Optimizations

2019 ◽  
Vol 26 (13) ◽  
pp. 2330-2355 ◽  
Author(s):  
Anutthaman Parthasarathy ◽  
Sasikala K. Anandamma ◽  
Karunakaran A. Kalesh
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Therapeutic Potential ◽  
The Past ◽  
Recombinant Production ◽  
Tremendous Progress ◽  
Recent Developments ◽  
Therapeutic Peptides ◽  
Development Processes ◽  
Delivery Strategies

Peptide therapeutics has made tremendous progress in the past decade. Many of the inherent weaknesses of peptides which hampered their development as therapeutics are now more or less effectively tackled with recent scientific and technological advancements in integrated drug discovery settings. These include recent developments in synthetic organic chemistry, high-throughput recombinant production strategies, highresolution analytical methods, high-throughput screening options, ingenious drug delivery strategies and novel formulation preparations. Here, we will briefly describe the key methodologies and strategies used in the therapeutic peptide development processes with selected examples of the most recent developments in the field. The aim of this review is to highlight the viable options a medicinal chemist may consider in order to improve a specific pharmacological property of interest in a peptide lead entity and thereby rationally assess the therapeutic potential this class of molecules possesses while they are traditionally (and incorrectly) considered ‘undruggable’.

Click Reactions in Chemistry of Triterpenes - Advances Towards Development of Potential Therapeutics

2018 ◽  
Vol 25 (5) ◽  
pp. 636-658 ◽  
Author(s):  
Jan Pokorny ◽  
Lucie Borkova ◽  
Milan Urban
Keyword(s):  
Biological Activities ◽  
Synthetic Approach ◽  
Clinical Use ◽  
New Approach ◽  
Click Reactions ◽  
Drug Candidates ◽  
The Past ◽  
Low Toxicity ◽  
New Compounds ◽  
Potential Therapeutics

Triterpenoids are natural compounds with a large variety of biological activities such as anticancer, antiviral, antibacterial, antifungal, antiparazitic, antiinflammatory and others. Despite their low toxicity and simple availability from the natural resources, their clinical use is still severely limited by their higher IC50 and worse pharmacological properties than in the currently used therapeutics. This fact encouraged a number of researchers to develop new terpenic derivatives more suitable for the potential clinical use. This review summarizes a new approach to improve both, the activity and ADME-Tox properties by connecting active terpenes to another modifying molecules using click reactions. Within the past few years, this synthetic approach was well explored yielding a lot of great improvements of the parent compounds along with some less successful attempts. A large quantity of the new compounds presented here are superior in both activity and ADME-Tox properties to their parents. This review should serve the researchers who need to promote their hit triterpenic structures towards their clinical use and it is intended as a guide for the chemical synthesis of better drug candidates.

Ionic Liquids for the Synthesis of Five-Membered N,N-, N,N,N- and N,N,N,NHeterocycles

2019 ◽  
Vol 23 (11) ◽  
pp. 1214-1238 ◽  
Author(s):  
Navjeet Kaur ◽  
Pranshu Bhardwaj ◽  
Meenu Devi ◽  
Yamini Verma ◽  
Neha Ahlawat ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Organic Synthesis ◽  
Heterocyclic Compounds ◽  
Reaction Medium ◽  
Environmental Issues ◽  
Organic Reaction ◽  
Environment Friendly ◽  
The Past ◽  
Area Of Interest ◽  
Major Subject

Due to special properties of ILs (Ionic Liquids) like their wide liquid range, good solvating ability, negligible vapour pressure, non-inflammability, environment friendly medium, high thermal stability, easy recycling and rate promoters etc. they are used in organic synthesis. The investigation for the replacement of organic solvents in organic synthesis is a growing area of interest due to increasing environmental issues. Therefore, ionic liquids have attracted the attention of chemists and act as a catalyst and reaction medium in organic reaction with high activity. There is no doubt that ionic liquids have become a major subject of study for modern chemistry. In comparison to traditional processes the use of ionic liquids resulted in improved, complimentary or alternative selectivities in organic synthesis. The present manuscript reported the synthesis of multiple nitrogen containing five-membered heterocyclic compounds using ionic liquids. This review covered interesting discoveries in the past few years.

Single Heterocyclic Compounds as Monoamine Oxidase Inhibitors: From Past to Present

2020 ◽  
Vol 20 (10) ◽  
pp. 908-920 ◽  
Author(s):  
Su-Min Wu ◽  
Xiao-Yang Qiu ◽  
Shu-Juan Liu ◽  
Juan Sun
Keyword(s):  
Monoamine Oxidase ◽  
Heterocyclic Compounds ◽  
Biological Activities ◽  
The Past ◽  
Structure Activity ◽  
Receptor Interactions ◽  
Heterocyclic Derivatives ◽  
Inhibitory Activities ◽  
Leading Compounds ◽  
Heterocyclic Moiety

Inhibitors of monoamine oxidase (MAO) have shown therapeutic values in a variety of neurodegenerative diseases such as depression, Parkinson’s disease and Alzheimer’s disease. Heterocyclic compounds exhibit a broad spectrum of biological activities and vital leading compounds for the development of chemical drugs. Herein, we focus on the synthesis and screening of novel single heterocyclic derivatives with MAO inhibitory activities during the past decade. This review covers recent pharmacological advancements of single heterocyclic moiety along with structure- activity relationship to provide better correlation among different structures and their receptor interactions.

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