Catalytic action of azolium salts. I. Aroylation of 4-chloro-1H-pyrazolo(3,4-d)pyrimidines with aromatic aldehydes catalyzed by 1,3-dimethylbenzimidazolium iodide.

Benzoin condensation of aromatic aldehydes catalysed by N,N-dimethylbenzimidazolium iodide and NaOH under green conditions

“…As shown in Scheme 1, the expected aroins 3a-d were obtained as major products together with the aroylaroins 4a-d as minor products. The aroylaroins 4a-d were resulted from further transformation of the corresponding aroins 3a-d by the mechanism reported 9 . After extraction of the products thus obtained with diethyl ether, the ionic liquid containing N,N -dimethylbenzimidazolium iodide (2) and NaOH could be reused, even after the third run without loss of activity, the same products were obtained with no obvious decrease in their yields.…”

Synthesis and Structural Characterization of the First Bis(benzimidazolin-2-ylidene) Complexes of Nickel(II)

“…Solvents were dried over Na/benzophenone (THF, diethyl ether, and toluene) or CaH 2 (CH 2 Cl 2 ). The N-substituted benzimidazoles 4 and 5 and the benzimidazolium halides 1 , 2 , and 6 were prepared according to literature procedures. ,− Elemental analyses (C, H, N) were performed on a Vario EL Elemental Analyzer and MALDI measurements on a Bruker Reflex IV instrument in DCTB matrix at the Department of Chemistry, WWU Münster.…”

Anwendungen der Katalyse mit N‐heterocyclischen Carbenen in Totalsynthesen

“…Miyashita et al beschrieben 1990 die carbenkatalysierte nucleophile Aroylierung von 4-Chlor-1H-pyrazolo [3,4-d]pyrimidinen. [74] In dieser Reaktion wirkt ein mithilfe eines NHC erzeugtes Acylanion als Nucleophil zur nucleophilen aromatischen Substitution. In den letzten 20 Jahren haben Miyashita, Suzuki und Mitarbeiter diese Reaktion zu einer allgemeinen Methode für die Synthese von aroylierten Verbin-dungen entwickelt.…”