Phosphorylation of 1-alkylmidazoles and 1-alkylbenzimidazoles with phosphorus(III) halides in the presence of bases

Abstract

Phosphorylation of 1-alkyl substituted imidazoles and benzimidazoles with P(III) halides in pyridine was shown to proceed at the 3-N atom of the heteroaryl ring and was followed by triethylamine-induced migration of the phosphorus group to the 2-C atom. Preparative methods were developed for the synthesis of a range of 2-phosphorylated derivatives of the indicated imidazoles. The latter were found to undergo alkylation either at P(III) or 3-N centers, depending on the alkylating agent.

Catalytic activity of 1‐methylimidazole‐based phosphine ligands in the palladium‐catalyzed Suzuki coupling reaction

“…All solvents were used after degassing with nitrogen. Phosphine ligands 1a–c (Fig. ) were prepared according to literature procedures.…”

Ruthenium piano-stool complexes bearing imidazole-based PN ligands

“…Compounds 1a,b,d -3a,b,d 32,33 and 1h 34 as well as [CpRu(PPh 3 ) 2 Cl] 35 and [CpRu(C 10 H 8 )]PF 6 36 were prepared according to literature procedures. All reactions were carried out in Schlenk tubes under an atmosphere of dry nitrogen using anhydrous solvents purified according to standard procedures.…”

The Phosphorus Aspects of Green Chemistry: the Use of Quaternary Phosphonium Salts and 1,3-Dialkylimidazolium Hexafluorophosphates in Organic Synthesis

“…Imidazolium phosphines attracted special interest due to the advantages opened in metal complex catalysis. P-substituted imidazolium ionic liquids were obtained in different ways [49][50][51][52][53]; one route involved direct deprotonation of commercial [bmim][PF 6 ] by BuLi followed by treatment with diphenylchlorophosphine (Scheme 19) [52,53]. Finally, the synthesis of imidazolium hexafluorophosphate salts with biodegradable substituents was also targeted [54].…”

“…The rate of the C-alkylation of N-diphenylmethyleneglycine esters increased greatly using 50 As regards Friedel-Crafts alkylation, immobilised scandium(III) triflate served as a novel and recyclable catalyst in [bmim][PF 6 ] as the solvent in the course of the alkylation of aromatic compounds (Scheme 56) [113].…”

“…Investigation on the acute toxicity and histological damage to zebrafish, Danio rerio, exposed to several ILs showed that imidazolium hexafluorophosphates can be regarded as not highly lethal in this instance (LC 50 96 h > 100 mg/L -1 ) [180].…”