scholarly journals Synthesis of 4-Substituted-1,2-Dihydroquinolines by Means of Gold-Catalyzed Intramolecular Hydroarylation Reaction of N-Ethoxycarbonyl-N-Propargylanilines

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3366
Author(s):  
Antonio Arcadi ◽  
Andrea Calcaterra ◽  
Giancarlo Fabrizi ◽  
Andrea Fochetti ◽  
Antonella Goggiamani ◽  
...  
Keyword(s):  
Building Blocks ◽  
Fine Tuning ◽  
Para Position ◽  
Cyclization Product ◽  
Synthetic Route ◽  
Substituted Anilines ◽  
Novel Approach ◽  
High Yields

An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-N-propargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-meta-substituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

scholarly journals A novel approach to the computation of one-loop three- and four-point functions: I. The real mass case

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
J Ph Guillet ◽  
E Pilon ◽  
Y Shimizu ◽  
M S Zidi
Keyword(s):  
Building Blocks ◽  
The Real ◽  
Alternative Method ◽  
Novel Approach ◽  
Reduction Methods ◽  
Real Mass ◽  
Novel Method ◽  
Algebraic Reduction ◽  
The One ◽  
Mass Case

Abstract This article is the first of a series of three presenting an alternative method of computing the one-loop scalar integrals. This novel method enjoys a couple of interesting features as compared with the method closely following ’t Hooft and Veltman adopted previously. It directly proceeds in terms of the quantities driving algebraic reduction methods. It applies to the three-point functions and, in a similar way, to the four-point functions. It also extends to complex masses without much complication. Lastly, it extends to kinematics more general than that of the physical, e.g., collider processes relevant at one loop. This last feature may be useful when considering the application of this method beyond one loop using generalized one-loop integrals as building blocks.

scholarly journals Automated Confirmation of Protein Annotation Using NLP and the UniProtKB Database

2020 ◽  
Vol 11 (1) ◽  
pp. 24
Author(s):  
Jin Tao ◽  
Kelly Brayton ◽  
Shira Broschat
Keyword(s):  
Language Processing ◽  
Fine Tuning ◽  
Support Vector ◽  
Protein Annotation ◽  
Computing Power ◽  
Journal Publication ◽  
Novel Approach ◽  
Uniprotkb Database ◽  
Public Repositories ◽  
Annotation Errors

Advances in genome sequencing technology and computing power have brought about the explosive growth of sequenced genomes in public repositories with a concomitant increase in annotation errors. Many protein sequences are annotated using computational analysis rather than experimental verification, leading to inaccuracies in annotation. Confirmation of existing protein annotations is urgently needed before misannotation becomes even more prevalent due to error propagation. In this work we present a novel approach for automatically confirming the existence of manually curated information with experimental evidence of protein annotation. Our ensemble learning method uses a combination of recurrent convolutional neural network, logistic regression, and support vector machine models. Natural language processing in the form of word embeddings is used with journal publication titles retrieved from the UniProtKB database. Importantly, we use recall as our most significant metric to ensure the maximum number of verifications possible; results are reported to a human curator for confirmation. Our ensemble model achieves 91.25% recall, 71.26% accuracy, 65.19% precision, and an F1 score of 76.05% and outperforms the Bidirectional Encoder Representations from Transformers for Biomedical Text Mining (BioBERT) model with fine-tuning using the same data.

scholarly journals Compiling Life-Oriented Moral Education Textbooks for Elementary Schools in China: The Mimetic Approach in Morality and Law

2021 ◽  
pp. 209653112098296
Author(s):  
Yan Tang
Keyword(s):  
Elementary Schools ◽  
Moral Education ◽  
Life Events ◽  
Theoretical Perspective ◽  
Building Blocks ◽  
Learning Activities ◽  
Design Approach ◽  
New Approach ◽  
Novel Approach

Purpose: This study explores a novel approach to compiling life-oriented moral textbooks for elementary schools in China, specifically focusing on Morality and Law. Design/Approach/Methods: Adopting Aristotle’s Poetics as its theoretical perspective, this study illustrates and analyzes the mimetic approach used in compiling the life-oriented moral education textbook, Morality and Law. Findings: The mimetic approach involves imitating children's real activities, thoughts, and feelings in textbooks. The mimetic approach to compiling life-oriented moral textbooks comprises three strategies: constructing children's life events as building blocks for textbook compilation, designing an intricate textual device exposing the wholeness of children's life actions, and designing inward learning activities leading to children's inner worlds. Originality/Value: From the perspective of Aristotle's Poetics, the approach to compilation in Morality and Law can be defined as mimetic. And the compilation activity in the life-oriented moral education textbook also can be described as a processes of mimesis. So this article presents a new approach to compile moral education textbooks, and  an innovative way to understand the nature of one compiling activity.

scholarly journals A two step synthesis of a key unit B precursor of cryptophycins by asymmetric hydrogenation

2011 ◽  
Vol 7 ◽  
pp. 243-245 ◽  
Author(s):  
Benedikt Sammet ◽  
Mathilde Brax ◽  
Norbert Sewald
Keyword(s):  
Asymmetric Hydrogenation ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
High Yields

A novel highly enantioselective two step access to a unit B precursor of cryptophycins in good yields from commercially available starting materials has been developed. The key step is an asymmetric hydrogenation using the commercially available [(COD)Rh-(R,R)-Et-DuPhos]BF4 catalyst. The synthetic route provides the advantage of less synthetic steps, proceeds with high yields and enantioselectivity, and avoids hazardous reaction conditions.

Efficient synthesis of polysubstituted 1,5-benzodiazepinone dipeptide mimetics via an Ugi-4CR-Ullmann condensation sequence

Synlett ◽  
2021 ◽  
Author(s):  
Robin Van Den Hauwe ◽  
Mathias Elsocht ◽  
Charlie Hollanders ◽  
Steven Ballet
Keyword(s):  
Building Blocks ◽  
Synthetic Route ◽  
Efficient Synthesis ◽  
Rapid Construction ◽  
Ligand Free

An efficient three step synthesis towards 3-amino-1,4-benzodiazepin-2-one derivatives is presented. The versatile Ugi-4-component reaction (Ugi-4CR) and Boc-deprotection is followed by a ligand-free Ullmann condensation. This protocol allows the rapid construction of a diverse array of substituted 1,5-benzodiazepinones. Since Ugi-based products are typically limited by their ‘inert’ C-terminal amides, the use of a convertible (‘cleavable’) isocyanide was envisaged and resulted in building blocks that can be made SPPS-compatible. To demonstrate the potential of this novel synthetic route, the design and preparation of novel phenylurea-1,5-bezondiazepin-4(5H)-one dipeptide mimetics with potential CCK2-antagonist properties is reported.

A Branch-and-Bound-Based Crossover Operator for the Traveling Salesman Problem

2019 ◽  
Vol 13 (3) ◽  
pp. 1-18
Author(s):  
Thomas Weise ◽  
Yan Jiang ◽  
Qi Qi ◽  
Weichen Liu
Keyword(s):  
Branch And Bound ◽  
Building Blocks ◽  
Extensive Study ◽  
The Body ◽  
Traveling Salesman ◽  
Crossover Operator ◽  
Novel Approach ◽  
Comparison Results ◽  
Population Sizes ◽  
The Traveling Salesman Problem

In this article, the new crossover operator BBX for Evolutionary Algorithms (EAs) for traveling salesman problems (TSPs) is introduced. It uses branch-and-bound to find the optimal combination of the (directed) edges present in the parent solutions. The offspring solutions created are at least as good as their parents and are only composed of parental building blocks. The operator is closer to the ideal concept of crossover in EAs than existing operators. This article provides the most extensive study on crossover operators on the TSP, comparing BBX to ten other operators on the 110 instances of the TSPLib benchmark set in EAs with four different population sizes. BBX, with its better ability to reuse and combine building blocks, surprisingly does not generally outperform the other operators. However, it performs well in certain scenarios. Besides presenting a novel approach to crossover on the TSP, the study significantly extends and refines the body of knowledge on the field with new conclusions and comparison results.

scholarly journals Functionalization of 4-bromobenzo[c][2,7]naphthyridine via regioselective direct ring metalation. A novel approach to analogues of pyridoacridine alkaloids

2019 ◽  
Vol 15 ◽  
pp. 2304-2310 ◽  
Author(s):  
Benedikt C Melzer ◽  
Alois Plodek ◽  
Franz Bracher
Keyword(s):  
Natural Products ◽  
Building Blocks ◽  
Novel Approach ◽  
Pyridoacridine Alkaloids

Readily available 4-bromobenzo[c][2,7]naphthyridine undergoes regioselective direct ring metalation at C-5 with TMPMgCl∙LiCl at −40 °C. Quenching with various electrophiles gives a broad range of 5-substituted products, which are building blocks for the synthesis of heterocyclic natural products and analogues thereof. In combination with a Parham-type cyclization a novel approach to pyrido[4,3,2-mn]acridones has been worked out.

scholarly journals Synthesis of acylglycerol derivatives by mechanochemistry

2019 ◽  
Vol 15 ◽  
pp. 811-817 ◽  
Author(s):  
Karen J Ardila-Fierro ◽  
Andrij Pich ◽  
Marc Spehr ◽  
José G Hernández ◽  
Carsten Bolm
Keyword(s):  
Amino Acids ◽  
Ball Milling ◽  
Mechanochemical Synthesis ◽  
Building Blocks ◽  
Synthetic Route ◽  
Biologically Relevant ◽  
Nucleotides And Nucleosides

In recent times, many biologically relevant building blocks such as amino acids, peptides, saccharides, nucleotides and nucleosides, etc. have been prepared by mechanochemical synthesis. However, mechanosynthesis of lipids by ball milling techniques has remained essentially unexplored. In this work, a multistep synthetic route to access mono- and diacylglycerol derivatives by mechanochemistry has been realized, including the synthesis of diacylglycerol-coumarin conjugates.

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