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Journal ArticleDOI

2‐Substituted 3‐dimethylamino‐ and ‐3‐cyanopropenoates in the synthesis of heterocyclic systems

01 Nov 1999-Journal of Heterocyclic Chemistry (Wiley‐Blackwell)-Vol. 36, Iss: 6, pp 1581-1593
About: This article is published in Journal of Heterocyclic Chemistry.The article was published on 1999-11-01. It has received 57 citations till now.
Citations
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Journal ArticleDOI
TL;DR: In this article, the main target of the microreview is to outline some of the reactive peculiarities that make 1,2-diaza-1,3-dienes reactive.

134 citations

Book ChapterDOI
TL;DR: In this paper, the molecular dimensions, molecular spectra, thermodynamic properties, tautomerism, and betain and mesoionic structures of 1,2,4-triazolo[1,5-a]pyrimidines are discussed.
Abstract: Publisher Summary 1,2,4-Triazolo[1,5-a]pyrimidines (TPs) play an important role in pharmaceutics, agrochemistry, photography, and other fields. They attract attention in synthetic, analytical, and theoretical chemistry. Isomeric 1,2,4-triazolo[4,3-a]pyrimidines and partially reduced TPs are mentioned only when they are precursors, potential intermediates, or reaction products of TPs. By far, the most TP syntheses are condensations of dinucleophilic 5-amino-1,2,4-triazoles (ATs) with 1,3-bifunctional synthons as in the formation of TP 2. Quantum-chemical calculations on TPs, particularly oxo compounds, were performed by several groups. A new aromaticity index was calculated for heterocyclic compounds. Comparison of the index of 2-ribosyl-5,7-dimethyl TP with that of the isomeric compound suggests that the driving force for the Dimroth rearrangement of the latter substance is the increase in aromatic character. The chapter discusses the molecular dimensions, molecular spectra, thermodynamic properties, tautomerism, and betain and mesoionic structures of TPs. The reactivity of TPs are described including triazolopyrimidines as bases and acids, ring alkylation, electrophilic reactions at carbon ring atoms, nucleophilic addition, ring cleavage, nucleophilic substitution of functional groups at the rings introduction and transformation of individual substituents, and reactivity of side chains. The pharmaceutical and agrochemical uses are described. The uses in information recording are also discussed.

74 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on the use of dimethylformamide dimethyl acetal in the preparation of heterocyclic compounds via formylation of active methylene groups, methyl groups to give enamines, and amino groups to giving amidines.

69 citations

Book ChapterDOI
TL;DR: Amino acids have been extensively used as important synthons for the syntheses of a variety of heterocyclic systems, especially for those in which one particular stereoisomer should be obtained via asymmetric synthesis.
Abstract: Amino acids (AAs) are usually considered as important scaffolds for peptides and proteins. However, in the past decades, they have been extensively used as important synthons for the syntheses of a variety of heterocyclic systems, especially for those in which one particular stereoisomer should be obtained via asymmetric synthesis. Although the applications of AAs as synthons in heterocyclization were extensively reviewed in 1995, numerous recent reports concerning their use for the construction of a wide variety of differently sized heterocycles make the subject worthwhile of update.

60 citations

References
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Journal ArticleDOI
TL;DR: A survey of Didehydroamino acids can be found in this paper, where synthesis, reactions, and spectroscopic investigations in the field of DIDEH amino acids are reviewed.
Abstract: Syntheses, reactions, and spectroscopic investigations in the field of didehydroamino acids published between 1982 and October 1987 are reviewed. A survey of natural compounds containing this subunit is also given. 1. Introduction 2. Syntheses of Didehydroamino Acids and Didehydropeptides 2.1. Syntheses via Elimination Reactions 2.2. Syntheses via C-C Bond Formation 3. Syntheses of Didehydropeptides by Amide Formation 3.1. Merrifield Peptide Synthesis 4. Isolation, Structure Elucidation, and Syntheses of Natural Products Containing Didehydroamino Acids 4.1. Syntheses of Peptide Hormones Containing Didehydroamino Acids 4.2. Didehydropeptides from Bacteria 4.3. Didehydropeptides from Fungi 4.4. Didehydropeptides from Marine Organisms 5. Reactions of Didehydroamino Acids 5.1. Reactions at the α,β-Double Bond 5.2. Reactions at the Carboxyl Function 5.3. Reactions at Nitrogen 6. Spectroscopic and Physical-Chemical Investigations of Didehydroamino Acids and Didehydropeptides

149 citations

Journal ArticleDOI
TL;DR: In this paper, alle wesentlichen Beitrage und Anderungen zur Kenntnis uber das naturliche Vorkommen von Aminosauren zusammenfassend darzustellen.
Abstract: Mit Hilfe moderner Trennungsmethoden sind in den letzten 15 Jahren zahlreiche neue Aminosauren entdeckt worden. Es wird versucht, alle wesentlichen Beitrage und Anderungen zur Kenntnis uber das naturliche Vorkommen von Aminosauren zusammenfassend darzustellen. Die Chemie und Biochemie der neuen Verbindungen sowie ihre Isolierung und Konstitutionsermittlung werden erlautert.

76 citations

Journal ArticleDOI
TL;DR: Methyl (Z)-2-acetylamino-3-dimethylaminopropenoate (3) was shown to be a versatile reagent in the synthesis of various heterocyclic systems as discussed by the authors.

40 citations