English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

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-ene-bis(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 Michael-type 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 .

zeitschrift für naturforschung b

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