Oxyazapeptides: Synthesis, Structure Determination, and Conformational Analysis
作者:Suvendu Biswas、Nader E. Abo-Dya、Alexander Oliferenko、Amir Khiabani、Peter J. Steel、Khalid A. Alamry、Alan R. Katritzky
DOI:10.1021/jo401234g
日期:2013.9.6
we report the synthesis, X-ray structure determination, and conformationalanalysis of a novel class of heteroatom-modified peptidomimetics, which we shall call “oxyazapeptides”. Substituting the typical native N-Cα bond with an O-Nα bond creates a completely new, previously unknown family of peptidomimetics, which are hydrolytically stable and display very interesting conformational behavior. Force
N,N′-Carbonyldiimidazole-Mediated DBU-Catalyzed One-Pot Synthesis of Urea-Tethered Glycosyl Amino Acids and Glycoconjugates
作者:V. Sureshbabu
DOI:10.1055/s-0030-1259958
日期:2011.5
An efficient, mild, simple, and alternative one-pot protocol for the synthesis of urea-tethered glycosyl amino acids mediated by N,N′-carbonyldiimidazole employing DBU as a catalyst is described. This protocol is also extended for the synthesis of urea-tethered disaccharides and oligosaccharides.
5-Substituted-3-(alkoxycarbonyl)alkyl-hydantoin derivatives were prepared by mechanochemistry from amino esters or dipeptides, via a 1,1′-carbonyldiimidazole-mediated one-pot/two-step cyclization reaction involving amino acid unsymmetrical urea A and carboxy-imidazolyl-dipeptide ester B intermediates. Comparative experiments in solution were also performed. The successful preparation of an antibacterial agent precursor
The mechanochemical preparation of highly functionalized 3,5-disubstituted hydantoins was investigated in the presence of various poly(ethylene) glycols (PEGs), as safe grinding assisting agents (liquid-assisted grinding, LAG). A comparative study under dry-grinding conditions was also performed. The results showed that the cyclization reaction was influenced by the amount of the PEG grinding agents
<i>N</i>-Alkyl Carbamoylimidazoles as Isocyanate Equivalents: Exploration of the Reaction Scope for the Synthesis of Ureas, Hydantoins, Carbamates, Thiocarbamates, and Oxazolidinones
作者:Jazmin Bansagi、Cody Wilson-Konderka、Vincent Debrauwer、Pournima Narayanan、Robert A. Batey
DOI:10.1021/acs.joc.2c00803
日期:2022.9.2
methyl ester and carbamoylimidazoles. The reaction of carbamoylimidazoles with alcohols and thiols under basic conditions affords carbamates and thiocarbamates, respectively, in good yields. Lastly, a method for the preparation of chiral oxazolidinone heterocycles from chiral epoxy alcohols is demonstrated using a double displacement approach. The reactions occur with high regio- and stereoselectivity