synthesis of N‐carbamoyl‐L‐aminoacids is reported. The procedure, involving the reaction between urea and α‐aminoacids sodium salts, was performed under microwave conditions using an unmodified domestic microwave oven. A careful study of the operative conditions indicated proline (1d) as the less reactive substrate and phenylglycine (1e) as the more reactive one among all the α‐aminoacids tested. Substitution
Quantitative N-deprotection without racemisation was then achieved in the solid through nitrosation by gaseous NOx. The extent of racemisation occurring in the coupling step is discussed. In the second application, an easy route to amino acid N-carboxy anhydrides (NCAs) through nitrosation of CAA under the same conditions as above allowed straightforward “one-pot” peptide stepwise coupling, as demonstrated
Microwave-Assisted Synthesis of N-Monosubstituted Urea Derivatives
作者:Lidia De Luca、Andrea Porcheddu、Giampaolo Giacomelli、Irene Murgia
DOI:10.1055/s-0030-1258553
日期:2010.10
An easy and rapid procedure for the preparation of N-monosubstituted ureas via reaction between potassium cyanate and a wide range of amines is described. The procedure was performed undermicrowaveirradiation using water as solvent. This methodology is particularly attractive since it provides ureas in high yield and purity.
Recent developments in peptide synthesis have underlined the importance of optimising, on a preparative scale, the N-carbamoylation of amino acids by aqueous cyanate. To this purpose, a theoretical model of aqueous cyanate reactivity was designed. The parameters of the model were evaluated, for various pH and temperatures, from a critical survey of the literature, together with additional experimental
Compositions of lipopeptide antibiotic derivatives and methods of use thereof
申请人:Cameron R. Dale
公开号:US20050153876A1
公开(公告)日:2005-07-14
The present invention provides derivatives of lipopeptide antibiotics that display antimicrobial activity against microorganisms, methods and compounds for synthesizing such antimicrobial derivatives and analogues, and methods of using the compounds in a variety of contexts, including in the treatment and prevention of microbial infections.