Orthoamide. LI. Push-Pull-Butadiene und Heterocyclen aus CH2-aciden Verbindungen und Orthoamiden von Alkincarbons�uren

Kantlehner, Willi; Vettel, Markus; Lehmann, Hansjörg; Edelmann, Kai; Stieglitz, Rüdiger; Ivanov, Ivo C.

doi:10.1002/prac.19983400503

Cited by 26 publications

(4 citation statements)

References 29 publications

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“…These alkynyl orthoamides are versatile synthetic building blocks in their own right. 9b, 19 It is hoped that propiolamidinium salts 3 will prove to be useful substrates for further transformations.…”

Section: Methodsmentioning

confidence: 99%

A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

Weingärtner¹,

Kantlehner²,

Maas³

2010

Synthesis

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Starting from N,N,N¢,N¢,N¢¢,N¢¢-hexaalkylguanidinium chlorides and terminal alkynes, a series of new orthoamide derivatives of alkynecarboxylic acids were prepared. The orthoamides were converted into propiolamidinium chlorides by reaction with benzoyl chloride and into propiolamidinium triflates by reaction with triethylsilyl trifluoromethanesulfonate. Propiolamidinium salts undergo conjugate addition reactions with sec-amines and thiols. Treatment of terminal alkyne chlorides with silver(I) oxide afforded a silver complex, which can apparently adopt the composition of either a bisalkynyl silver complex [Ag(CCC(NMe 2 ) 2 ) 2 ]AgCl 2 or a monoalkynyl silver complex [ClAgCCC(NMe 2 ) 2 ].

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Section: Methodsmentioning

confidence: 99%

A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

Weingärtner¹,

Kantlehner²,

Maas³

2010

Synthesis

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“…11,12,19 These results were explained by the assumption that in the first step propiolamidinium ions and carbanions are formed from the starting compounds by loss of dimethylamine. The ketene aminals 32 result from the ionic species thus formed via conjugated addition.…”

Section: Hydrolysis Of the Orthoamide 7amentioning

confidence: 99%

Orthoamides and iminium salts, LXXIII1. Contributions to the cleavage of carboxylic acid orthoamides – a new access to N,N,N‘,N‘-tetraalkyl-carboxamidinium salts

Kantlehner¹,

Lehmann²,

Stieglitz³

2012

Arkivoc

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Orthoamides 7b-e of alkyne carboxylic acids are transformed by benzoyl chloride to give the corresponding amidinium chlorides 13b-f, which were isolated as the tetraphenylborates 14. The reaction of the orthoamide derivative of phenylpropiolic acid 7a with acetic acid anhydride results in the formation of the acylated ketene aminal 20. The orthoamide of propiolic acid 22 and chloroform react, affording the vinylogous guanidinium salt 24. By the hydrolysis of the orthoamide derivative of phenylpropiolic acid 7a the β-keto-carboxylic acid amide 31A, which is in equilibrium with its enol form 31B, was obtained. Primary and secondary amines react with the phenylpropiolamidinium chloride 13a under conjugated addition, delivering vinylogous guanidinium salts 33.

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“…However, the registration of the 13 C NMR spectra of compounds 36 and 37 with longer relaxation times from 1 s to 10 and 20 s and a larger number of scans, as recommended, did not improve the signal intensity. Spectral comparison with unsubstituted-and 4-phenyl-substituted 2-pyridone [17] and 4-methyl-6-dimethylamino-2-pyridone and 4-dimethylamino-6-methyl-2-pyridone [40] was not sufficient for the unambiguous structural identification of compounds 36 and 37.…”

Section: Synthesis Of the C-nucleoside Analogsmentioning

confidence: 99%

Orthoamides and Iminium Salts, LXXX [1]. C-Glycosyl Alkynecarboxylic Acid Orthoamides. Versatile Intermediates in the Synthesis of New Types of Highly Substituted C-Nucleoside Analogs

Drandarov

Kantlehner

2012

Zeitschrift Für Naturforschung B

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The C-glycosyl alkynecarboxylic acid orthoamides 22 and 23 are proposed as versatile precursors for the synthesis of new types of C-nucleoside analogs. The new synthetic strategy includes alkynylation of protected aldoses 13 or ketoses by Grignard ethynylation or Barbier propargylation, O-protection of the resulting alkynols 14-16, and nucleophilic addition of the metalated protected terminal alkynes 20 and 21 to peralkylguanidinium salt 2 to afford the corresponding alkynecarboxylic acid orthoamides 22 and 23, which in reactions with mono or bis-nucleophiles could serve as building blocks for the construction of a wide variety of C-nucleoside-like binary conjugates. All the steps are demonstrated on 2,4,3,5-bis(4-methoxybenzylidene)-protected L-xylose 11 as a model compound. The synthesis of a representative series of C-glycosidic conjugates of highly substituted "push-pull" 1,3-butadienes 32-35, pyrimidines 24-31, and 2-pyridones 36-39 is included. The stereochemistry of all described compounds is established by 2D-NMR techniques. A general character of the proposed synthetic strategy, when applied to different appropriately protected sugar derivatives, is suggested, and a biomedical applicability of the described type of conjugates is expected.

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Orthoamide. LI. Push-Pull-Butadiene und Heterocyclen aus CH2-aciden Verbindungen und Orthoamiden von Alkincarbons�uren

Cited by 26 publications

References 29 publications

A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

A Convenient Synthesis and Some Characteristic Reactions of Novel Propiolamidinium Salts

Orthoamides and iminium salts, LXXIII1. Contributions to the cleavage of carboxylic acid orthoamides – a new access to N,N,N‘,N‘-tetraalkyl-carboxamidinium salts

Orthoamides and Iminium Salts, LXXX [1]. C-Glycosyl Alkynecarboxylic Acid Orthoamides. Versatile Intermediates in the Synthesis of New Types of Highly Substituted C-Nucleoside Analogs

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