19962-06-2Relevant articles and documents
Copolymers of aniline and 3-aminophenol derivatives with oligo(oxyethylene) side chains as novel water-soluble conducting polymers
Hua, Fengjun,Ruckenstein, Eli
, p. 6104 - 6112 (2004)
A novel water-soluble copolymer of aniline and aminophenol (AP) grafted with oligo(oxyethylene) (PEO) side chains (AP-g-PEO) was synthesized. The AP-g-PEO macromononer was prepared starting from an N-protected 3-aminophenol (protection group: tert-butoxycarbonyl) followed by the substitution of tosylated oligo(oxyethylene) on the hydroxide moiety of the AP and deprotection. Finally, AP-g-PEO was copolymerized with aniline at various feed mole ratios (AP-g-PEO/aniline), The copolymers and various intermediates were characterized by FTIR, MS, NMR, GPC, UV-vis, and chemical elemental analysis. The increase of the aniline content and the decrease of the PEO side chain length generated lower oligo(oxyethylene) grafted concentrations and solubilities in water but longer conjugation lengths and higher conductivities. Four AP-g-PEOs were prepared from four oligo(oxyethylene) methyl ethers with Mn = 164, 350, 750, and 2000. The poly((AP-g-PEO-750)-co-aniline) at a feed mole ratio of 3/1 was water-soluble and possessed a relatively high conductivity (0.12 S/cm). AP-g-PEOs were found to have low reactivities and to generate low homopolymerization degrees because of the torsional effects of the PEO side chains on the backbone of the copolymer. A possible copolymerization mechanism was suggested. Furthermore, the copolymers with high PEO content had lower oxidation and doping levels of their backbones, which were confirmed by X-ray photoelectron spectroscopy.
Ultrasound promoted environmentally benign, highly efficient, and chemoselective N-tert-butyloxycarbonylation of amines by reusable sulfated polyborate
Pise, Ashok S.,Ingale, Ajit P.,Dalvi, Navnath R.
supporting information, p. 3768 - 3780 (2021/10/26)
The sulfated polyborate catalyzed an efficient and chemoselective N-tert-butyloxycarbonylation of amines under ultrasonic irradiation is developed. A broad substrate scope has been demonstrated for N-Boc protection of various primary/secondary amines. It allows converting several aliphatic/aryl/heteroaryl amines, amino alcohol, aminoester, and chiral amines to their N-Boc-protected derivatives under solvent-free conditions with excellent yields. The protocol has several advantages such as easy catalyst, and product isolation, short reaction time, excellent yields, outstanding chemoselectivity, and catalyst recyclability, among others. This makes the process practicable, economical, and environmentally benign.
Thiamine hydrochloride as a recyclable organocatalyst for the efficient and chemoselective N-tert-butyloxycarbonylation of amines
Ingale, Ajit P.,Garad, Dnyaneshwar N.,Ukale, Dattatraya,Thorat, Nitin M.,Shinde, Sandeep V.
supporting information, p. 3791 - 3804 (2021/11/04)
Thiamin hydrochloride promoted highly efficient and ecofriendly approach has been described for the chemoselective N-tert-butyloxycarbonylation of amines under solvent-free conditions at ambient temperature. The demonstrated approach has been applicable for the N-Boc protection of variety of aliphatic, aryl, heteroaryl amines. The chemoselective protection of amino group occurs in chiral amines and amino alcohol without racemization in high yield. Thiamin hydrochloride is stable, economical, easy to handle and environmentally friendly.