108212-53-9Relevant articles and documents
Chitosan grafted with a heteropolyanion-based ionic liquid as an effective and reusable catalyst for acetalization
Zhang, Wei-Hong,Liu, Shan-Shan,Liu, Ping,Xu, Jie,Xue, Bing,Wei, Xian-Yong,Li, Yong-Xin
, p. 41404 - 41409 (2016/05/19)
Chitosan immobilized with an acidic ionic liquid (CS-VImPS-PW) was fabricated via a radical addition reaction of N-vinylimidazoliumpropane sulfonate and chitosan, followed by acidification with a heteropolyacid. It was characterized by a Fourier transform infrared spectrometer, solid-state 13C nuclear magnetic resonance spectrometer, thermogravimetric analyzer, elemental analyzer, and Hammett indicator. Some acetalization reactions were investigated to evaluate the catalytic activity of CS-VImPS-PW. The results show that CS-VImPS-PW is highly active for the acetalization reactions in high acetal yields ranging from 83.2 to 96.2% and can be reused 8 times without noticeable loss of activity.
Indium metal as a reducing agent in organic synthesis
Pitts,Harrison,Moody
, p. 955 - 977 (2007/10/03)
The low first ionisation potential (5.8 eV) of indium coupled with its stability towards air and water, suggest that this metallic element should be a useful reducing agent for organic substrates. The use of indium metal for the reduction of C=N bonds in imines, the heterocyclic ring in benzo-fused nitrogen heterocycles, of oximes, nitro compounds and conjugated alkenes and the removal of 4-nitrobenzyl protecting groups is described. Thus the heterocyclic ring in quinolines, isoquinolines and quinoxalines is selectively reduced using indium metal in aqueous ethanolic ammonium chloride. Treatment of a range of aromatic nitro compounds under similar conditions results in selective reduction of the nitro groups; ester, nitrile, amide and halide substituents are unaffected. Likewise indium in aqueous ethanolic ammonium chloride is an effective method for the deprotection of 4-nitrobenzyl ethers and esters. Indium is also an effective reducing agent under non-aqueous conditions and α-oximino carbonyl compounds can be selectively reduced to the corresponding N-protected amine with indium powder, acetic acid in THF in the presence of acetic anhydride or di-tert-butyl dicarbonate. Conjugated alkenes are also reduced by indium in THF-acetic acid.
Efficient Method for the Reductive Cleavage of Acetals and Ketals with Zn(BH4)2/Me3SiCl
Kotsuki, Hiyoshizo,Ushio, Yasuyuki,Yoshimura, Naka,Ochi, Masamitsu
, p. 2594 - 2596 (2007/10/02)
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