Revisiting the Urech Synthesis of Hydantoins: Direct Access to Enantiopure 1,5-Substituted Hydantoins Using Cyanobenziodoxolone
作者:Nina Declas、Franck Le Vaillant、Jerome Waser
DOI:10.1021/acs.orglett.8b03843
日期:2019.1.18
synthesis of enantiopure 1,5-substituted hydantoins was developed using a hypervalent iodine cyanation reagent (cyanobenziodoxolone, CBX) as a source of electrophilic carbon. Starting from inexpensive commercially available enantiopure protected amino acids, the method allowed the synthesis of various hydantoins without epimerization. Formation of hydantoins from dipeptides was also possible, but partial
Cu-catalyzed <i>N</i>-3-Arylation of Hydantoins Using Diaryliodonium Salts
作者:Linn Neerbye Berntsen、Ainara Nova、David S. Wragg、Alexander H. Sandtorv
DOI:10.1021/acs.orglett.0c00642
日期:2020.4.3
A general Cu-catalyzed, regioselective method for the N-3-arylation of hydantoins is described. The protocol utilizes aryl(trimethoxyphenyl)iodonium tosylate as the arylating agent in the presence of triethylamine and a catalytic amount of a simple Cu-salt. The method is compatible with structurally diverse hydantoins and operates well with neutral aryl groups or aryl groups bearing weakly donating/withdrawing
Mechanochemical Preparation of Hydantoins from Amino Esters: Application to the Synthesis of the Antiepileptic Drug Phenytoin
作者:Laure Konnert、Benjamin Reneaud、Renata Marcia de Figueiredo、Jean-Marc Campagne、Frédéric Lamaty、Jean Martinez、Evelina Colacino
DOI:10.1021/jo5017629
日期:2014.11.7
eco-friendly preparation of 5- and 5,5-disubstituted hydantoins from various amino ester hydrochlorides and potassium cyanate in a planetary ball-mill is described. The one-pot/two-step protocol consisted in the formation of ureido ester intermediates, followed by a base-catalyzed cyclization to hydantoins. This easy-handling mechanochemical methodology was applied to a large variety of α- and β-amino esters
Cu-catalyzed C(sp<sup>2</sup>)–N-bond coupling of boronic acids and cyclic imides
作者:Linn Neerbye Berntsen、Thomas Nordbø Solvi、Kristian Sørnes、David S. Wragg、Alexander H. Sandtorv
DOI:10.1039/d1cc04356k
日期:——
Cu-t the Ru. A general Cu-catalyzed method for (E)-enimide-formation is described. The process is mild and practical, and couples cyclic imides and alkenylboronic acids. The method can also be used to prepare N-arylimides.
Chain Initiation Efficiency in Cobalt- and Nickel-Mediated Polypeptide Synthesis
作者:Timothy J. Deming、Scott A. Curtin
DOI:10.1021/ja994281q
日期:2000.6.1
In the presence of certain ligands and solvents, nickel- and cobalt-mediated living polymerizations of α-aminoacid-N-carboxyanhydrides (NCAs) produce polymers with molecular weights several times greater than predicted by initial molar ratios of monomer to initiator. Such molecular weight inflation could result either from competitive formation of catalytic intermediates of reduced activity or from