scholarly journals A practical two-step procedure for the preparation of enantiopure pyridines: Multicomponent reactions of alkoxyallenes, nitriles and carboxylic acids followed by a cyclocondensation reaction

2011 ◽  
Vol 7 ◽  
pp. 962-975 ◽  
Author(s):  
Christian Eidamshaus ◽  
Roopender Kumar ◽  
Mrinal K Bera ◽  
Hans-Ulrich Reissig
Keyword(s):  
Lactic Acid ◽  
Carboxylic Acids ◽  
Multicomponent Reaction ◽  
Multicomponent Reactions ◽  
Practical Approach ◽  
Side Chains ◽  
Step Process ◽  
Step Procedure ◽  
Cyclocondensation Reaction

A practical approach to highly functionalized 4-hydroxypyridine derivatives with stereogenic side chains in the 2- and 6-positions is described. The presented two-step process utilizes a multicomponent reaction of alkoxyallenes, nitriles and carboxylic acids to provide β-methoxy-β-ketoenamides which are transformed into 4-hydroxypyridines in a subsequent cyclocondensation. The process shows broad substrate scope and leads to differentially substituted enantiopure pyridines in good to moderate yields. The preparation of diverse substituted lactic acid derived pyrid-4-yl nonaflates is described. Additional evidence for the postulated mechanism of the multicomponent reaction is presented.

scholarly journals Concise Synthesis of Macrocycles by Multicomponent Reactions

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 1027-1038 ◽  
Author(s):  
Alexander Dömling ◽  
Eman Abdelraheem ◽  
Samad Khaksar
Keyword(s):  
Amino Acid ◽  
Multicomponent Reaction ◽  
Ring Opening ◽  
Multicomponent Reactions ◽  
Reaction Pathway ◽  
Ring Closure ◽  
Side Chains ◽  
Reaction Sequence ◽  
Cyclic Anhydride

A short reaction pathway was devised to synthesize a library of artificial 18–27-membered macrocycles. The five-step reaction sequence involves ring opening of a cyclic anhydride with a diamine, esterification, coupling with an amino acid isocyanide, saponification, and, finally, macro-ring closure using an Ugi or, alternatively, a Passerini multicomponent reaction. Three out of the five steps allow for the versatile introduction of linker elements, side chains, and substituents with aromatic, heteroaromatic, and aliphatic character. The versatile pathway is described for 15 different target macrocycles on a mmol scale. Artificial macrocycles have recently become of great interest due to their potential to bind to difficult post-genomic targets.

scholarly journals Doebner-type pyrazolopyridine carboxylic acids in an Ugi four-component reaction

2019 ◽  
Vol 15 ◽  
pp. 1281-1288
Author(s):  
Maryna V Murlykina ◽  
Oleksandr V Kolomiets ◽  
Maryna M Kornet ◽  
Yana I Sakhno ◽  
Sergey M Desenko ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Carboxylic Acids ◽  
Multicomponent Reaction ◽  
Multicomponent Reactions ◽  
Compound Library ◽  
Reaction Sequence ◽  
Scaffold Diversity ◽  
Substituted 1

Substituted 1H-pyrazolo[3,4-b]pyridine-4- and 1H-pyrazolo[3,4-b]pyridine-6-carboxamides have been synthetized through a Doebner–Ugi multicomponent reaction sequence in a convergent and versatile manner using diversity generation strategies: combination of two multicomponent reactions and conditions-based divergence strategy. The target products contain as pharmacophores pyrazolopyridine and peptidomimetic moieties with four points of diversity introduced from readily available starting materials including scaffold diversity. A small focused compound library of 23 Ugi products was created and screened for antibacterial activity.

scholarly journals An evaluation of credentials of a multicomponent reaction for the synthesis of isothioureas through the use of a holistic CHEM21 green metrics toolkit

2017 ◽  
Vol 19 (1) ◽  
pp. 249-258 ◽  
Author(s):  
S. Abou-Shehada ◽  
P. Mampuys ◽  
B. U. W. Maes ◽  
J. H. Clark ◽  
L. Summerton
Keyword(s):  
Organic Compounds ◽  
Multicomponent Reaction ◽  
Multicomponent Reactions ◽  
Materials Used

Multicomponent reactions (MCRs) are considered green and material efficient methods for the synthesis of organic compounds, however very few studies have investigated the metrics of the upstream processes involved to achieve the starting materials used in these reactions.

Pot, atom and step-economic (PASE) synthesis of medicinally relevant spiro[oxindole-3,4′-pyrano[4,3-b]pyran] scaffold

2016 ◽  
Vol 22 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Michail N. Elinson ◽  
Fedor V. Ryzhkov ◽  
Victor A. Korolev ◽  
Mikhail P. Egorov
Keyword(s):  
Multicomponent Reaction ◽  
Multicomponent Reactions ◽  
Large Scale ◽  
Potassium Fluoride ◽  
Environmentally Benign ◽  
Anti Hiv

AbstractFast (3 min) pot, atom and step economics (PASE) potassium fluoride catalyzed multicomponent reaction of isatins, malononitrile and 4-hydroxy-6-methyl-2H-pyran-2-one results in efficient formation of substituted spirooxindole-3,4′-pyrano[4,3-b]pyrans in 92–96% yields. The developed ‘on-solvent’ approach to the substituted spirooxindole-3,4′-pyrano[4,3-b]pyrans – the pharmacologically perspective substances with known antiviral, antileishmanial, anticonvulsant and anti-HIV activities – is beneficial from the viewpoint of diversity-oriented large-scale processes and represents fast and environmentally benign synthetic concept for the multicomponent reactions strategy.

The Process of Interpretation

2019 ◽  
pp. 152-176 ◽  
Author(s):  
Brian A. Sharpless
Keyword(s):  
Positive Outcome ◽  
Clinical Vignette ◽  
The Unconscious ◽  
Step Process ◽  
Therapy Approach ◽  
Expressive Therapy ◽  
Step Procedure ◽  
Potential Risks ◽  
And Behaviors

Interpretations are efforts by the therapist to connect conscious (or preconscious) feelings, thoughts, and behaviors (e.g., symptoms) to the unconscious materials that gave rise to them. Interpretations may consist of therapist observations or the presentation of a hypothesis that goes beyond what the patient already knows. Interpretations are often considered to be the epitome of the expressive therapy approach and, when done well, have been empirically linked to a positive outcome. Unfortunately, many beginning therapists are reluctant to use interpretations due to their complexity. Therefore, this chapter describes a clear, six-step procedure for generating psychodynamic interpretations and presenting them to patients. It also includes a list of questions for therapists to answer as they organize patient material. The chapter concludes with a lengthy clinical vignette following the six-step process and a discussion of the potential risks and rewards of interpretation.

scholarly journals Synthesis of Biologically Active Molecules through Multicomponent Reactions

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 505 ◽  
Author(s):  
Daniel Insuasty ◽  
Juan Castillo ◽  
Diana Becerra ◽  
Hugo Rojas ◽  
Rodrigo Abonia
Keyword(s):  
Multicomponent Reaction ◽  
Biological Property ◽  
Multicomponent Reactions ◽  
Organic Molecules ◽  
Biological Activities ◽  
Biologically Active ◽  
Vast Number ◽  
Key Points ◽  
Reported Data ◽  
Synthetic Approaches

Focusing on the literature progress since 2002, the present review explores the highly significant role that multicomponent reactions (MCRs) have played as a very important tool for expedite synthesis of a vast number of organic molecules, but also, highlights the fact that many of such molecules are biologically active or at least have been submitted to any biological screen. The selected papers covered in this review must meet two mandatory requirements: (1) the reported products should be obtained via a multicomponent reaction; (2) the reported products should be biologically actives or at least tested for any biological property. Given the diversity of synthetic approaches utilized in MCRs, the highly diverse nature of the biological activities evaluated for the synthesized compounds, and considering their huge structural variability, much of the reported data are organized into concise schemes and tables to facilitate comparison, and to underscore the key points of this review.

Inhibition of Fusarium culmorum by carboxylic acids released from lactic acid bacteria in a barley malt substrate

Food Control ◽  
2016 ◽  
Vol 69 ◽  
pp. 227-236 ◽  
Author(s):  
Lorenzo C. Peyer ◽  
Claudia Axel ◽  
Kieran M. Lynch ◽  
Emanuele Zannini ◽  
Fritz Jacob ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Carboxylic Acids ◽  
Fusarium Culmorum ◽  
Barley Malt

Synthesis and hydrolytic degradation of graft copolymers containing poly(lactic acid) side chains

2002 ◽  
Vol 76 (3) ◽  
pp. 411-417 ◽  
Author(s):  
Valérie Langlois ◽  
Karine Vallee-Rehel ◽  
Jean Jacques Peron ◽  
Alain le Borgne ◽  
Michael Walls ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Graft Copolymers ◽  
Hydrolytic Degradation ◽  
Poly Lactic Acid ◽  
Side Chains

Production of Short-Chain Carboxylic Acids by Co-Digestion of Swine Manure and Corn Silage: Effect of Carbon-Nitrogen Ratio

2020 ◽  
Vol 63 (2) ◽  
pp. 445-454 ◽  
Author(s):  
Qitao Cao ◽  
Wanqin Zhang ◽  
Yunhao Zheng ◽  
Tianjing Lian ◽  
Hongmin Dong
Keyword(s):  
Lactic Acid ◽  
Carboxylic Acids ◽  
Agricultural Waste ◽  
Swine Manure ◽  
Corn Silage ◽  
Short Chain ◽  
Fuel Production ◽  
Energy Value ◽  
Unit Energy ◽  
Acid Producing Bacteria

HighlightsThe maximum SCCA concentration was achieved at a C/N ratio of 25 with 18 days of fermentation.The highest VFAs and LA were produced at C/N ratios of 12.7 and 35, respectively, after 12 days of fermentation.The unit energy value of SCCAs for drop-in fuel production was 50.5% higher than that of methane.The dominant bacteria changed from Clostridium to Lactobacillus with increasing C/N ratio.Abstract. Advancing technologies to produce short-chain carboxylic acids (SCCAs) from agricultural waste are expected to be more economical and efficient. This study presented a new attempt to enhance SCCA production from co-digestion of swine manure and corn silage with the carbon-nitrogen (C/N) ratio adjusted from 12.7 to 50.2. Results showed that the maximum SCCA concentration of 26,214 ±2948 mg COD L-1 was achieved at a C/N ratio of 25 with 18 days of digestion, and the concentrations of lactic acid (LA) and volatile fatty acids (VFAs) were 8700 ±1060 mg COD L-1 and 17,514 ±1888 mg COD L-1, respectively. The LA content first increased and then slightly decreased with increasing C/N ratio, and the maximum LA concentration was 468.5 ±44.3 mg COD g-1 VSadded (VSadded means added fermentation material is calculated as volatile solids) at a C/N ratio of 35 at 12 days of digestion. VFAs showed an opposite trend, with a maximum VFA concentration of 601.1 ±42.4 mg COD g-1 VSadded found at a C/N ratio of 12.7 after 12 days of digestion. Potential energy analysis of the highest SCCA production showed that the unit energy value of SCCAs for drop-in fuel production was 50.5% higher than that of methane. Analysis of the microbial community showed that the dominant bacterial groups changed gradually from butyric acid-producing bacteria (Clostridium) to lactic acid-producing bacteria (Lactobacillus) as the C/N ratio increased from 12.7 to 50.2. Keywords: Anaerobic digestion, Corn silage, Lactic acid, Short-chain carboxylic acids, Swine manure.

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