MECHANISM OF GUANIDINE NITRATION: I. AZO-BIS-NITROFORMAMIDINE

1952 ◽  
Vol 30 (1) ◽  
pp. 62-70 ◽  
Author(s):  
George F Wright
Keyword(s):  
Nitric Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Secondary Amines ◽  
Similar Reaction ◽  
Imino Group ◽  
Diels Alder Reaction ◽  
Soluble Compound ◽  
Dinitro Derivative ◽  
Entire Sequence

Although azo-bis-formamidine dinitrate cannot be converted to the dinitro derivative directly it can be chlorinated in water to azo-bis-chloroformamidine and thence to azo-bis-nitroformamidine in nitric acid and acetic anhydride. When the latter substance is treated with 2-methylpentadiene-1,3 an alkali-soluble compound is obtained which is specified as 1-imino-3-nitrimino-4,6(or 5,7)-dimethyl-2,8,9-triaza-4,6,8,9-tetrahydroindandione-1,3. The characteristics of this reaction indicate that azo-bis-nitroformamidine exists as the nitrimino tautomer. The Diels-Alder reaction with 2-methylpentadiene-1,3 has its counterpart in the similar reaction whereby azo-bis-formamidine is converted to 1,3-diimino-4,6-dimethyl-2,8,9-triaza-4,6,8,9-tetrahydroindandione-1,3mononitrateand ammonium nitrate. The entire sequence of reactions is offered as evidence that the imino group in guanidines is the site of nitration, and its chemistry of nitration is analogous with that of aliphatic secondary amines.

scholarly journals Cycloadditionen, XX Thermisch induzierte intramolekulare Reaktionen bei 2-Methyl-2,3-butadienamiden / Cycloadditions, XX Thermally Induced Intramolecular Reactions of 2-Methyl-2,3-butadienamides

1992 ◽  
Vol 47 (12) ◽  
pp. 1785-1794 ◽  
Author(s):  
Gerhard Himbert ◽  
Hans-Jürgen Schlindwein
Keyword(s):  
Double Bond ◽  
Alder Reaction ◽  
Diels Alder ◽  
Secondary Amines ◽  
Thermally Induced ◽  
Methyl Group ◽  
Diels Alder Reaction ◽  
Intramolecular Reactions ◽  
Derivatives Of ◽  
Allenic Acid

The 2-methyl-2,3-butadienamides 4a—m are directly synthesized by the reaction of the corresponding allenic acid chloride 2 with the secondary amines 3. At heating, 4a—j undergo the intramolecular Diels-Alder reaction, by using their ω-standing double bond and the π-system of the directly bonded phenyl groups or of the “methylenic” bonded arenes or furans. Thereby the tricycles 6a—g (bearing five-membered lactam moreties) and/or the tricycles 7-9 (bearing six-membered lactam moreties) are formed. The influence of the geminai methyl group on the chemoselectivity and on the velocity of the IMDA reactions is investigated. The N-allyl derivatives of 4 (s. 41 and m) form the bicycles 10 by intramolecular [2+2]-Cycloaddition.

Simple Synthesis of Complex Amines from the Diels–Alder Adducts of (–)-Cytisine

Synthesis ◽  
2021 ◽  
Author(s):  
Alexander Shivanyuk ◽  
Alexey Chuyko ◽  
Grygoriy Dolgonos ◽  
Volodymyr Fetyukhin ◽  
Oleg Lukin
Keyword(s):  
Quantum Chemical ◽  
Alder Reaction ◽  
Diels Alder ◽  
Secondary Amines ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Carbonyl Groups ◽  
Model Compounds ◽  
Reaction Progress ◽  
Diels Alder Reaction

AbstractThe Diels–Alder reaction of N-benzylcytisine with N-methyl- and N-benzylmaleimides is 100% endo-selective and gives the corresponding syn- and anti-diastereomers in 11–42% isolated yields. The studies of the reaction progress with LCMS and NMR along with detailed quantum chemical calculations revealed that some Diels–Alder adducts are kinetically and their isomers are thermodynamically controlled products. The Pd/C-catalyzed hydrogenation of benzyl-protected cytisine amine derivatives resulted in the removal of the benzyl group and the addition of hydrogen to the C=C double bond to give the corresponding secondary amines in 45–84% yield. The complete reduction of carbonyl groups in a cytisine derivative with LiAlH4 in THF under reflux afforded the respective tricyclic triamine. Quantum mechanical calculations for the mechanism of the Diels–Alder reaction between the simplest model compounds are presented.

Stabilization of Simple Imines by Coordination to Ruthenium(II), and Aspects of Their Reactivity

1986 ◽  
Vol 39 (12) ◽  
pp. 2027 ◽  
Author(s):  
GW Whebell ◽  
FR Keene
Keyword(s):  
Electrochemical Properties ◽  
Alder Reaction ◽  
Diels Alder ◽  
Secondary Amines ◽  
Metal Centre ◽  
Diels Alder Reaction ◽  
Aromatic Species ◽  
Back Bonding ◽  
Dehydrogenation Reactions ◽  
Imine Ligands

The oxidation of a number of secondary amines coordinated to ruthenium(II) was investigated. Pyrrolidine (1) and piperidine (5) formed the corresponding 1-imines [1-pyrroline (2) and 2,3,4,5- tetrahydropyridine (6)]; these complexes were stable, although spectral and electrochemical properties show there to be only minor π-back- bonding between the RuII metal centre and the imine ligands. The analogous β-unsaturated amines [3-pyrroline (3) and 1,2,3,6- tetrahydropyridine (7)] complexes also underwent oxidative dehydrogenation reactions, and in these cases produced the corresponding aromatic species [pyrrole (4) and pyridine (8), respectively]. Coordinated N-methylallylamine (9) was oxidized to a mixture of the two possible 1-imine species (10) and (11), and preliminary studies indicated that the 1-aza 1,3-diene (11) product would undergo a Diels-Alder reaction while attached to the metal centre.

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

The intermolecular anthracene-transfer in a regiospecific antipodal C60 difunctionalization

2020 ◽  
Author(s):  
Radu Talmazan ◽  
Klaus R. Liedl ◽  
Bernhard Kräutler ◽  
Maren Podewitz
Keyword(s):  
Noncovalent Interactions ◽  
Interaction Model ◽  
Alder Reaction ◽  
Diels Alder ◽  
Stacking Interactions ◽  
Pi Stacking ◽  
Diels Alder Reaction ◽  
Double Decker ◽  
Anthracene Molecule ◽  
New Strategies

We analyze the mechanism of the topochemically controlled difunctionalization of C60 and anthracene, where an anthracene molecule is transferred from one C60 monoadduct to another one under exclusive formation of equal amounts of C60 and the difficult to make antipodal C60 bisadduct. Our herein disclosed dispersion corrected DFT studies show the anthracene transfer to take place in a synchronous retro Diels-Alder/Diels-Alder reaction: an anthracene molecule dissociates from one fullerene under formation of an intermediate, while already undergoing stabilizing interactions with both neighboring fullerenes, facilitating the reaction kinetically. In the intermediate, a planar anthracene molecule is sandwiched between two neighboring fullerenes and forms equally strong "double-decker" type pi-pi stacking interactions with both of these fullerenes. Analysis with the distorsion interaction model shows that the anthracene unit of the intermediate is almost planar with minimal distorsions. This analysis sheds light on the existence of noncovalent interactions engaging both faces of a planar polyunsaturated ring and two convex fullerene surfaces in an unprecedented 'inverted sandwich' structure. Hence, it sheds light on new strategies to design functional fullerene based materials.<br>

Natural Products Biosynthesis Involving a Putative Diels-Alder Reaction

2016 ◽  
Vol 20 (22) ◽  
pp. 2421-2442 ◽  
Author(s):  
Kévin Cottet ◽  
Maria Kolympadi ◽  
Dean Markovic ◽  
Marie-Christine Lallemand
Keyword(s):  
Natural Products ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction

Aza-Diels-Alder Reaction Between 1,2-Diaza-1,3-dienes and β-Aryl-α,β-unsaturated Carbonyl Compounds. Easy One-pot Entry to 2’-Oxo-imidazo[1’,5’- f]tetrahydropyridazine

2014 ◽  
Vol 10 (6) ◽  
pp. 951-960
Author(s):  
Orazio Attanasi ◽  
Luca Bianchi ◽  
Maurizio D’Auria ◽  
Gianfranco Favi ◽  
Fabio Mantellini ◽  
...  
Keyword(s):  
Carbonyl Compounds ◽  
Alder Reaction ◽  
Diels Alder ◽  
One Pot ◽  
Diels Alder Reaction

Enantioselective Syntheses of Flavonoid Diels-Alder Natural Products: A Review

2018 ◽  
Vol 15 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Shah Bakhtiar Nasir ◽  
Noorsaadah Abd Rahman ◽  
Chin Fei Chee
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Enantioselective Synthesis ◽  
Chiral Ligand ◽  
Asymmetric Syntheses ◽  
Diels Alder Reaction ◽  
Enantioselective Syntheses

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.

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