title: Evaluation of carbodiimides using a competition method.
abstract: A competitive reaction of activated Boc-Ala-OH and Boc-Phe-OH with H-Leu-resin has been developed for assessing the relative efficiencies of different carbodiimides. This allowed a comparison of the efficiency of the carbodiimides N,N'-dicyclohexylcarbodiimide,N,N'-diisopropylcarbodiimide, N-tert-butyl-N'-methylcarbodiimide and N-tert-butyl-N'-ethylcarbodiimide. Comparable results were obtained when these reagents were used for the preformation of symmetrical anhydrides or of 1-hydroxybenzotriazole esters in situ. Differential incorporation was observed when asymmetrical carbodiimides were used for peptide bond formation by the direct carbodiimide procedure.
authors.affiliation: Department of Chemistry, University of Warsaw, Poland.
authors.forename: J
authors.initials: J
authors.lastname: Izdebski
authors.forename: D
authors.initials: D
authors.lastname: Kunce
mesh_terms: D000409:Alanine / Q000737:chemistry; D049148:Aminoacylation; D002234:Carbodiimides / Q000737:chemistry*; D004024:Dicyclohexylcarbodiimide / Q000737:chemistry; D007202:Indicators and Reagents; D007930:Leucine / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D010649:Phenylalanine / Q000737:chemistry; D012116:Resins, Plant
chemical_list: D002234:Carbodiimides; D007202:Indicators and Reagents; D010455:Peptides; D012116:Resins, Plant; D010649:Phenylalanine; D004024:Dicyclohexylcarbodiimide; C081611:1,3-diisopropylcarbodiimide; D007930:Leucine; D000409:Alanine