Synthesis of Iminium Salts, Orthoesters and Related Compounds

Kantlehner, Willi

doi:10.1016/b978-0-08-052349-1.00166-9

Cited by 34 publications

(9 citation statements)

References 784 publications

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“…Imidates, also known as imidoates, imidic acid esters, or imido esters, are known to be important pharmacophores and useful synthetic building blocks . Whereas most of the present synthetic approaches take advantage of Pinner-type reactions, some difficulties are often encountered such as low yields and rather limited substrate scope.…”

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confidence: 99%

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

et al. 2006

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[reaction: see text] It is shown that N-sulfonylimidates can be efficiently prepared by a three-component coupling of terminal alkynes, sulfonyl azides, and alcohols with use of a copper catalyst and an amine base. The reaction is characterized by mild conditions, high selectivity, and tolerance with various functional groups. Facile transformation of imidates to amidines was also achieved by sodium cyanide. Additionally, a protocol for the extremely efficient Pd-catalyzed [3,3]-sigmatropic rearrangement of allylic sulfonimidates to N-allylic sulfonamides has been developed.

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confidence: 99%

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

et al. 2006

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“…In the course of the VR both reactants, the N, N-disubstitued formamides 1 and the acid chlorides 2, are transformed into reactive chloroformamidinium chlorides 3 which are able to react with suitable nucleophilic substrates, like an aromatic or heteroaromatic compound of the general formula 4, to yield, in a first step, the corresponding iminium salts 5 [4] from which Scheme 1. Formation of iminium salts 5 and aldehydes 6.…”

Section: Introductionmentioning

confidence: 99%

On the Formation and ¹H NMR-spectroscopic Characterization of N,N-Diaryl-substituted Formamide Chlorides

Schönewerk

Hartmann

2012

Zeitschrift Für Naturforschung B

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“…N,N,N′,N′-peralkylated amidinium salts are of general interest in preparative organic chemistry [37][38][39], because they can be used for the preparation of nearly all kinds of orthoamide derivatives [40] and ketene aminals [41,42], which are of high synthetic importance. Thus, the precursors for very useful formylating reagents, such as N,N-dimethylformamide acetals, the Bredereck-Simchen esters, or tris(dialkylamino)methanes, are N,N,N′,N′-tetraalkyl-formamidinium salts.…”

Section: Introductionmentioning

confidence: 99%

Orthoamides and iminium salts, LXXXIX. Reactions of N,N,N′,N′,N″,N″,N′″,N′″-octamethyl-acetylene-bis(carboxamidinium) tetrafluoroborate with nucleophilic reagents – new methods for the preparation of amidinium salts and ketene aminalsa

Drandarov

Tiritiris

Kantlehner³

2015

Zeitschrift Für Naturforschung B

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The acetylene-bis(carboxamidinium) salt 4 dehydrates carboxylic acids to the corresponding anhydrides, as the byproduct 2-oxo-but-2-en-amidinium salt 6b was isolated. Aromatic hydroxy compounds and 2-furyl-methylmercaptan add to the triple bond of the salt 4 to give 2-aryloxy-and 2-alkylmercapto-but-2-enebis(amidinium) salts 7-9. According to this reaction principle, 2-organoamino-buten-2-ene-bis(amidinium) salts 10 and 11 were prepared from 4 and primary and secondary amines, whereas 4-chlorobenzhydrazide reacted with 4 to give the imidazole-3-carboxamidinium salt 13. The reaction of CH 2 -acidic compounds as malononitrile or ethyl cyanoacetate with the bis(amidinium) salt 4 affords 2-cyanomethylene-but-3-enamidinium salts 15. With the CH-acidic diethyl 2-bromomalonate, compound 4 undergoes a Michael-initiated ring closure cyclopropenation reaction with further ring opening by the released Br -to the corresponding 2-diethoxycarbonylmethylene-3-bromo-but-3-enamidinium salt 18. Unlike cyclopentadiene and furane, the reaction of N-methylpyrrole and bis(amidinium) salt 4 does not lead to Diels-Alder [4 + 2] cycloadduct but to the Michaeltype 1:1 adduct 20. Pyrrole-and thiophene-2-carboxamidinium salts 23-25 can be prepared from compound 4 and esters of glycine, N-methylglycine (sarcosine), and mercaptoacetic acid, respectively. The derivatives of quinoxaline-2-carboxamidinium salts 29 are accessible from aromatic 1,2-diamines and compound 4. The reaction of the CH 2 /NH-acidic cyanoacetamide with the bis(amidinium) salt 4 produced the 3-pyrroline-2-on derivatives 33.

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Synthesis of Iminium Salts, Orthoesters and Related Compounds

Cited by 34 publications

References 784 publications

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

On the Formation and ¹H NMR-spectroscopic Characterization of N,N-Diaryl-substituted Formamide Chlorides

Orthoamides and iminium salts, LXXXIX. Reactions of N,N,N′,N′,N″,N″,N′″,N′″-octamethyl-acetylene-bis(carboxamidinium) tetrafluoroborate with nucleophilic reagents – new methods for the preparation of amidinium salts and ketene aminalsa

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Synthesis of Iminium Salts, Orthoesters and Related Compounds

Cited by 34 publications

References 784 publications

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

A Facile Access to N-Sulfonylimidates and Their Synthetic Utility for the Transformation to Amidines and Amides

On the Formation and 1H NMR-spectroscopic Characterization of N,N-Diaryl-substituted Formamide Chlorides

Orthoamides and iminium salts, LXXXIX. Reactions of N,N,N′,N′,N″,N″,N′″,N′″-octamethyl-acetylene-bis(carboxamidinium) tetrafluoroborate with nucleophilic reagents – new methods for the preparation of amidinium salts and ketene aminalsa

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On the Formation and ¹H NMR-spectroscopic Characterization of N,N-Diaryl-substituted Formamide Chlorides