Oligomerization of Aromatic Tertiary Amines

Abstract

The oligomerization of some tertiary aromatic amines was studied using ferric chloride in a variety of solvent. The predominant dimer formation of triphenylamine (TPA) was observed in chloroform at 0 °C where concentration of TPA was 0.125 mmol/l and the molar ratio of ferric chloride to TPA was 4. Except for N-methyldiphenylamine, high molecular weight oligomers were formed in a variety of solvents.

Oxidative coupling polymerization of 4-methyltriphenylamine

“…Polymerization was carried out at 50 8C in the presence of 4 mol equivalent of ferric chloride under nitrogen atmosphere in chloroform (CL) or propylene carbonate (PC), which were conventionally purified. As we reported, the low temperature (0 -20 8C) and the use of a larger amount of ferric chloride preferably yielded a dimer (p-TPD) in A 90% yield 8) . Tab.…”

“…1 (b), mainly 8 signals were observed in the aromatic region for a high molecular weight polymer (2-2), which means that coupling reactions occurred exclusively at para position of unsubstituted N-phenyl rings, and a linear structure as shown in Fig. 1 was obtained. Moreover, the chemical shift of each signal is reasonable assuming the linear structure and taking the assignment of a dimer, p-TPD, into account 8) . The additional small signals 10 -18 observed clearly in low molecular weight polymer (1) are assignable to monomer units at the polymer chain end.…”

“…Nickel-catalyzed coupling reaction between aryl bromide and aryl Grignard reagent has been also applied to synthesize a branched poly(triphenylamine) 7) . Recently we reported that triarylamine dimers like N,N9-diphenyl-N,N9-bis(4-methylphenyl)benzidine (p-TPD) were simply and selectively prepared in high yield by chemical oxidative coupling of triarylamines using ferric chloride 8) . In this work, an oxidative coupling reaction is applied to obtain a linear poly(triarylamine).…”

Recent Uses of Iron (III) Chloride in Organic Synthesis

“…In the particular case of ferric chloride, Sato and co-workers have described the oligomerisation of a variety of aromatic tertiary amines 1 by chemical oxidative coupling using FeCl 3 (Scheme 1) [8]. In the particular case of ferric chloride, Sato and co-workers have described the oligomerisation of a variety of aromatic tertiary amines 1 by chemical oxidative coupling using FeCl 3 (Scheme 1) [8].…”

Stereoselective Synthesis of the β‐Amino Acid Moiety of Fijiolide A

“…The stereoselective synthesis of -amino acids is an intensively studied area. [4] Previous synthetic work by Hirama [5] and Cramer [6] relied on diastereomeric 1,4-addition of Davies lithium amide to cinnamic acid ester 4 to yield 5 or asymmetric hydrogenation of respective enamine 6 which was transformed into amino acid 3 (Scheme 1). Our synthetic plan for amino acid 3 is based on oxidative ring opening of oxathiazinane 9, which could be obtained by enantioselective C-H amination of sulf-Scheme 1.…”