138088-28-5Relevant articles and documents
A photoactivated precipiton for reagent sequestration in solution-phase synthesis
Bosanac, Todd,Wilcox, Craig S.
, p. 4194 - 4195 (2002)
Precipitons are molecular phase tags for chemical separations. They can be switched from a high-solubility to a low-solubility state to facilitate product, reagent, or catalyst isolation. This paper presents the first photoactivated precipiton and demonstrates that this precipiton is an efficient amine scavenging agent in solution-phase syntheses of amides, ureas, and imines. This approach to amine scavenging offers advantages over solid-phase scavenging methods. The amine is captured in a homogeneous medium, so the capture is much faster than seen with isocyanate resins, and only a small excess of the scavenger is required. Copyright
Enantioselective synthesis of 3,5-disubstituted thiohydantoins and hydantoins
Chen, Yu,Su, Li,Yang, Xinying,Pan, Wenyan,Fang, Hao
, p. 9234 - 9239 (2015/11/27)
A mild method to convert optically pure amino acid thiourea and urea derivatives to thiohydantoins and hydantoins, respectively, is described. It provides an efficient way to realize enantioselective synthesis of thiohydantoins and hydantoins with good to high isolated yields and enantiomeric purities. We found that the enantiomeric purities were highly dependent on the reaction conditions including bases, solvents, and temperature.
Synthesis of novel chiral cholic acid-based molecular tweezers containing unsymmetrically disubstituted urea units using microwave irradiation
Zeng, Bitao,Zhao, Zhigang,Zhou, Lijun,Li, Qinghan
scheme or table, p. 206 - 209 (2012/09/08)
An efficient procedure has been developed for the synthesis of new chiral cholic acid molecular tweezer artificial receptors by linking an unsymmetrically disubstituted urea to methyl deoxycholate via a carbonate chain using microwave irradiation. The structures of these new receptors were confirmed by 1H NMR, IR, MS spectra and elemental analysis. Their binding properties were examined by UV-Vis spectra titration. The preliminary results indicate that these molecular tweezers not only recognised anions, but also showed good enantioselectivity for D-amino acid methyl esters.