92515-43-0Relevant articles and documents
Asymmetric solution-phase mixture aldol reaction using oligomeric ethylene glycol tagged chiral oxazolidinones
Turkyilmaz, Serhan,Wilcox, Craig S.
supporting information, p. 2031 - 2033 (2017/05/04)
Sorting tags are oligomeric structures that can be used as protecting groups or chiral auxiliaries enabling solution-phase mixture syntheses of multiple tagged compounds in one pot and allowing for facile and predictable chromatographic separation of products at the end of synthetic sequences. Perfluorinated hydrocarbon and oligomeric ethylene glycol (OEG) derivatives are known classes of sorting tags. Herein we describe the preparation of OEGylated chiral oxazolidinones and their use in asymmetric solution-phase mixture aldol reactions. Through the use of such oxazolidinones based on tyrosine four different individually tagged aldol adducts were obtained as a mixture, chromatographically demixed, detagged, and it was shown that these processes gave the desired aldol products in good yield and enantioselectivity.
Indium(III) halides as new and highly efficient catalysts for N-tert-butoxycarbonylation of amines
Chankeshwara, Sunay V.,Chakraborti, Asit K.
, p. 2784 - 2788 (2008/02/05)
Indium(III) bromide and chloride efficiently catalysed the N-tert-butoxycarbonylation of amines with (Boc)2O at room temperature and under solvent-free conditions. Various aromatic, heteroaromatic and aliphatic amines were converted to N-tert-butylcarbamates in excellent yields in short times. Chiral amines, esters of α-amino acids and β-amino alcohols afforded optically pure N-t-Boc derivatives in high yields. The reactions were chemoselective and no competitive side reactions such as isocyanate, urea, and N,N-di-t-Boc formation were observed. Chemoselective conversion to N-tert-butylcarbamates took place with amino alcohols without any formation of oxazolidinones. Georg Thieme Verlag Stuttgart.
Copper(II) tetrafluoroborate as a novel and highly efficient catalyst for N-tert-butoxycarbonylation of amines under solvent-free conditions at room temperature
Chankeshwara, Sunay V.,Chakraborti, Asit K.
, p. 1087 - 1091 (2007/10/03)
Commercially available copper(II) tetrafluoroborate hydrate was found to be a highly efficient catalyst for chemoselective N-tert-butoxycarbonylation of amines with di-tert-butyl dicarbonate under solvent-free conditions and at room temperature. Various aromatic amines were protected as their N-tert-butyl carbamates in high yields and in short times. No competitive side reactions such as isocyanate, urea, and N,N-di-t-Boc formation was observed. Chemoselective N-tert-butoxycarbonylation was achieved with substrates bearing OH and SH groups. Chiral α-amino acid esters afforded the corresponding N-t-Boc derivatives in excellent yields.
HClO4-SiO2 as a new, highly efficient, inexpensive and reusable catalyst for N-tert-butoxycarbonylation of amines
Chakraborti, Asit K.,Chankeshwara, Sunay V.
, p. 2769 - 2771 (2008/03/28)
Perchloric acid adsorbed on silica-gel (HClO4-SiO2) was found to be a new, highly efficient, inexpensive and reusable catalyst for chemoselective N-tert-butoxycarbonylation of amines at room temperature and under solvent-free conditions. The Royal Society of Chemistry 2006.
A practical synthesis of enantiopure (S)-4-(4-hydroxybenzyl)-oxazolidin-2-one
Green, Rachel,Taylor, Piers J. M.,Bull, Steven D.,James, Tony D.,Mahon, Mary F.,Merritt, Andy T.
, p. 2619 - 2623 (2007/10/03)
A high yielding four-step synthesis of enantiopure 4-(4-hydroxybenzyl)-oxazolidin-2-one (S)-1 from N-Boc-L-tyrosine is described. (S)-1 is a key intermediate for the preparation of a number of polymer supported Evans' oxazolidin-2-ones that have been employed previously for solid supported asymmetric synthesis.
Synthesis of cancer peptide antigen-lipid A analog conjugates for synthetic vaccines
Ikeda, Kiyoshi,Miyajima, Keisuke,Maruyama, Yasufumi,Achiwa, Kazuo
, p. 563 - 568 (2007/10/03)
Conjugates 6 and 7 of cancer peptide antigen with N-tetradecanoyl L- serine-β-alanine-containing D-glucosamine derivative structurally related to lipid A as an immunoadjuvant were synthesized for the development of totally synthetic vaccines against cancers. The mitogenic activities of compounds 6 and 7 were stronger than that of lipid A analog 3.
Peptide Synthesis in Aqueous Solution. V. Properties and Reactivities of (p-Hydroxyphenyl)benzylmethylsulfonium Salts for Direct Benzyl Esterification of N-Acylpeptides
Nakata, Takashi,Nakatani, Masaru,Takahashi, Masatoshi,Okai, Jiro,Kawaoka, Yoshiaki,Kouge, Katsushige,Okai, Hideo
, p. 1099 - 1106 (2007/10/03)
Some (p-hydroxyphenyl)benzylmethylsulfonium salts were prepared. These compounds generated a benzyl cation and converted not only N-acylamino acids but also N-acylpeptides into their corresponding benzyl esters without causing the racemization.
