scholarly journals Development of fully-automated synthesis systems

1994 ◽  
Vol 16 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Tohru Sugawara ◽  
Shinji Kato ◽  
Shigeha Okamoto
Keyword(s):  
Organic Chemistry ◽  
High Pressure ◽  
Chemical Reactions ◽  
Pharmaceutical Compounds ◽  
Additional Benefit ◽  
Automated Synthesis ◽  
User Friendly

This paper describes the development of fully-automated synthesis systems for preparing and isolating various kinds of pharmaceutical compounds. The systems are versatile, and are able to perform most of the chemical reactions currently used in organic chemistry, with the exception of hydrogenation which requires high pressure. An additional benefit is the very user-friendly software.

scholarly journals Extraction of organic chemistry grammar from unsupervised learning of chemical reactions

2021 ◽  
Vol 7 (15) ◽  
pp. eabe4166
Author(s):  
Philippe Schwaller ◽  
Benjamin Hoover ◽  
Jean-Louis Reymond ◽  
Hendrik Strobelt ◽  
Teodoro Laino
Keyword(s):  
Organic Chemistry ◽  
Neural Networks ◽  
Chemical Synthesis ◽  
Unsupervised Learning ◽  
Chemical Reactions ◽  
Data Driven ◽  
Experimental Task ◽  
Rule Based ◽  
Atom Mapping ◽  
Mapping Information

Humans use different domain languages to represent, explore, and communicate scientific concepts. During the last few hundred years, chemists compiled the language of chemical synthesis inferring a series of “reaction rules” from knowing how atoms rearrange during a chemical transformation, a process called atom-mapping. Atom-mapping is a laborious experimental task and, when tackled with computational methods, requires continuous annotation of chemical reactions and the extension of logically consistent directives. Here, we demonstrate that Transformer Neural Networks learn atom-mapping information between products and reactants without supervision or human labeling. Using the Transformer attention weights, we build a chemically agnostic, attention-guided reaction mapper and extract coherent chemical grammar from unannotated sets of reactions. Our method shows remarkable performance in terms of accuracy and speed, even for strongly imbalanced and chemically complex reactions with nontrivial atom-mapping. It provides the missing link between data-driven and rule-based approaches for numerous chemical reaction tasks.

Data augmentation and transfer learning strategies for reaction prediction in low chemical data regimes

2021 ◽  
Author(s):  
Yun Zhang ◽  
Ling Wang ◽  
Xinqiao Wang ◽  
Chengyun Zhang ◽  
Jiamin Ge ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Deep Learning ◽  
Drug Discovery ◽  
Research And Development ◽  
Learning Strategies ◽  
Transfer Learning ◽  
Chemical Reactions ◽  
Data Augmentation ◽  
Learning Method ◽  
Reaction Prediction

An effective and rapid deep learning method to predict chemical reactions contributes to the research and development of organic chemistry and drug discovery.

Activation and control of chemical reactions at very high pressure

2008 ◽  
Vol 78 (5) ◽  
pp. 058104 ◽  
Author(s):  
V Schettino ◽  
R Bini ◽  
M Ceppatelli ◽  
M Citroni
Keyword(s):  
High Pressure ◽  
Chemical Reactions ◽  
And Control ◽  
Very High

scholarly journals Liquid-phase exfoliated graphene: functionalization, characterization, and applications

2014 ◽  
Vol 5 ◽  
pp. 2328-2338 ◽  
Author(s):  
Mildred Quintana ◽  
Jesús Iván Tapia ◽  
Maurizio Prato
Keyword(s):  
Organic Chemistry ◽  
Liquid Phase ◽  
Chemical Reactions ◽  
Functional Materials ◽  
Atomic Plane ◽  
Graphene Sheets ◽  
Exfoliated Graphene ◽  
Graphene Functionalization ◽  
Chemical Strategies ◽  
Insight Into

The development of chemical strategies to render graphene viable for incorporation into devices is a great challenge. A promising approach is the production of stable graphene dispersions from the exfoliation of graphite in water and organic solvents. The challenges involve the production of a large quantity of graphene sheets with tailored distribution in thickness, size, and shape. In this review, we present some of the recent efforts towards the controlled production of graphene in dispersions. We also describe some of the chemical protocols that have provided insight into the vast organic chemistry of the single atomic plane of graphite. Controlled chemical reactions applied to graphene are expected to significantly improve the design of hierarchical, functional platforms, driving the inclusion of graphene into advanced functional materials forward.

scholarly journals The Principle of Conservation of Structural Aspect: Facilitating Visual Communication and Learning in Organic Chemistry Instruction

2019 ◽  
Author(s):  
john andraos
Keyword(s):  
Organic Chemistry ◽  
Chemical Reactions ◽  
Reaction Mechanisms ◽  
Visual Communication ◽  
Structural Aspect ◽  
Chemical Bonds ◽  
Journal Articles ◽  
Chemistry Instruction ◽  
Individual Reaction ◽  
Training Exercises

<p>An effective pedagogical method is presented for the visual communication of chemical reactions learned in organic chemistry undergraduate courses. The basis for the method is the preservation of the visual aspect of reactant and product structures so that the tracking of cleaved and formed chemical bonds is made self-evident. This consequently leads to improved clarity of presentation and a better understanding and grasp of proposed reaction mechanisms to explain product outcomes. The method is demonstrated for a variety of individual reaction types and synthesis plans. Various visual training exercises are also presented using ChemDraw Ultra 7.0 software and literature table of contents (TOC) graphics appearing in journal articles.</p><br>

scholarly journals The The perceptions of Senior High School students and teachers about organic chemistry: A Ghanaian perspective

2021 ◽  
Vol 32 (4) ◽  
pp. 331-342
Author(s):  
Esther Nartey ◽  
◽  
Ruby Hanson ◽  
Keyword(s):  
Organic Chemistry ◽  
High School ◽  
High School Students ◽  
Chemical Reactions ◽  
Simple Random Sampling ◽  
Senior High School ◽  
Future Research ◽  
Positive Perception ◽  
School Students ◽  
Teachers Perceptions

The purpose of the study was to determine the perceptions that senior high school (SHS) chemistry students and teachers have about organic chemistry as well as to compare organic chemistry topics that are difficult for students and teachers. Simple random sampling (lottery) and purposive sampling methods were used to select a sample of one hundred (100) SHS students who studied elective chemistry and ten (10) chemistry teachers. The research instruments used to collect data for this study were the ‘organic chemistry perceptions questionnaire for students’ (OCPQS) and ‘organic chemistry perceptions questionnaire for teachers’ (OCPQT). Descriptive statistics (frequencies and percentages) were used to analyze the data collected. The findings revealed that these SHS students have a fairly positive perception of organic chemistry while their teachers had a highly positive perception of organic chemistry. Preparation and chemical reactions of alkenes, preparation and chemical reactions of alkynes, structure and stability of benzene, reactions of benzene, comparison of reactions of benzene and alkenes, petroleum, polymers and naming of alkanes and structural isomerism were perceived by students as difficult to understand. The rest of the Ghanaian SHS organic chemistry topics (26 out of 34 topics) were perceived as easy to understand by students. Also, the teachers perceived all the SHS organic chemistry topics as easy to teach with the exception of reactions of benzene. The insights gained about teachers’ and students’ perceived difficult organic chemistry topics in this study imply that teachers’ perceptions and how these are communicated to students can have significant effects on learning. The authors believe that both teachers and learners could benefit from this increased awareness of perceptions about difficulties in teaching and learning organic chemistry. They therefore suggest that further studies into how teachers’ perceptions influence their teaching and consequently their students’ experiences be carried out. In addition, in future research, a diagnostic test based on the topics in the SHS organic chemistry syllabus could be added to ascertain whether the perceived difficult topics are actually difficult for students to answer questions on. This would help teachers to separate perceived difficulties from the actual difficulties (realities) and be able to address them in their lessons.

Kinetics of electrolytic hydrogen and deuterium evolution

1960 ◽  
Vol 256 (1284) ◽  
pp. 128-144 ◽  
Keyword(s):  
Organic Chemistry ◽  
Chemical Reactions ◽  
Isotopic Ratio ◽  
Deuterium Substitution ◽  
Electrolytic Hydrogen ◽  
Kinetics Of ◽  
Mechanism Operative

The use of deuterium substitution for hydrogen in reactants as a means for elucidation of mechanisms of chemical reactions has been extensively employed in organic chemistry (Wiberg 1955; Roginsky 1956). A previous paper (Conway 1958) presented calculations of the isotopic ratio R of exchange currents (t0) in cathodic reactions evolving hydrogen and deuterium for limiting cases and showed that a characteristic dependence of R upon the rate-determining mechanism operative in the overall reaction could, under certain conditions, be expected.

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