1-Aza-1,3-bis(triphenylphosphoranylidene)propane: A Novel :CHCH2N: Synthon

A facile route to the synthesis of polyfunctionalized pyrroles

“…3 Recently, syntheses of polysubstituted pyrroles have been reported from conjugate addition reactions, 4 transition metal intermediates, 5 reductive coupling, 6 aza Wittig reactions, 7 isocyanide-based reactions, 8 utilizing the sila-Stetter/Paal-Knorr sequence strategy 9 and other useful pathways. 10 Three-component reaction between triphenylphosphine, dialkyl acetylenedicarboxylates (DAAD's) and organic acidic compounds is well known to produce phosphorus ylides.…”

The Application of Iron (Iii) Phosphate in the Synthesis of N-Substituted Pyrroles

“…Consequently, many methods for the synthesis of diversely substituted pyrroles have been developed such as montmorillonite, KSF 12 , microwave irradiation 13,14 , Bi(NO 3 ) 3 .5H 2 O 15 , Sc(OTf) 3 16 , TolSO 3 H 17 , layered zirconium phosphate and zirconium sulfophenyl phosphonate 18 , titanium 19 or TiCl 4 /Et 3 N 20 . Some of other methods for synthesis of pyrroles include: conjugate addition reactions 21 , annulation reactions 22,23 , multicomponent reactions 24,25 and aza-Wittig reactions 26 . However, several of these methods require prolonged reaction times, use of volatile organic solvents and toxic metals.…”

Cobalt(II) chloride as a novel and efficient catalyst for the synthesis of 1,2,5‐trisubstituted pyrroles under solvent‐free conditions

“…Despite their importance from a pharmacological, industrial, and synthetic point of view, comparatively few methods for their preparation have been reported [4]. Of the current methods such as Hantzsch [5], Knorr [6], and aza-Witting reactions [7], the Paal-Knorr [8] reaction is one of the most simple and straightforward methods for the synthesis of N-substituted pyrroles. Many catalysts have been used to promote the Paal-Knorr reaction such as Ti(OiPr) 4 [9], A1 2 O 3 [10], Bi(NO 3 ) 3 [ll], Bi(OTf) 3 [12], Sc(OTf) 3 [13], montmorillonite-KSF [14], and others [15].…”