Unusual Reactivity of Dimethylsulfoxonium Methylide with Esters
作者:Antonella Leggio、Rosaria De Marco、Francesca Perri、Mariagiovanna Spinella、Angelo Liguori
DOI:10.1002/ejoc.201101031
日期:2012.1
The dimethylsulfoxonium methylide was treated with esters under mild conditions to rapidly afford the corresponding carboxylic acids at room temperature. Moreover, by performing the procedure on enantiopure substrates, it was demonstrated that the reaction occurs without racemization. 18O-labeled reagents showed that the reaction does not proceed through an ester hydrolysis mechanism. The reactions
HIV protease inhibitors based on amino acid derivatives
申请人:——
公开号:US20020151546A1
公开(公告)日:2002-10-17
A compound selected from the group consisting of a compound of formula I
1
a compound of formula II
2
and when the compound of formula I and II comprises an amino group pharmaceutically acceptable ammonium salts thereof, wherein R
1
, R
2
, Cx, n, R
3
, R
4
, R
5
, Y are as defined in the specification.
<i>N</i>-Methylation of Peptides on Selected Positions during the Elongation of the Peptide Chain in Solution Phase
作者:M. Luisa Di Gioia、Antonella Leggio、Angelo Liguori
DOI:10.1021/jo0478959
日期:2005.5.1
and general solution-phase method for the site-specific N-methylation of peptides has been developed. This novel procedure involves synthesis of N-nosyl protected peptides and their subsequent N-methylation with diazomethane. Its efficiency was proved by the successful synthesis of various hindered oligopeptides containing N-methyl amino acid residues with excellent yield and purity. The method is
作者:Emilia Belsito、Maria L. Di Gioia、Antonella Greco、Antonella Leggio、Angelo Liguori、Francesca Perri、Carlo Siciliano、Maria C. Viscomi
DOI:10.1021/jo070438i
日期:2007.6.1
N-methyl-N-nosyl-α-aminoacyldiazomethanes provides the corresponding N-methyl-N-nosyl-β3-amino acids with total retention of the chiral configuration of the starting α-amino acids. No epimerization of the chiral carbon atom is observed also when N-methyl-N-nosyl-β3-amino acids are transformed into chlorides and coupled with α-amino acid methyl esters to achieve model scaffolds for biologically important modified peptides
One-pot synthesis of amides from carboxylic acids activated using thionyl chloride
作者:A. Leggio、E. L. Belsito、G. De Luca、M. L. Di Gioia、V. Leotta、E. Romio、C. Siciliano、A. Liguori
DOI:10.1039/c5ra24527c
日期:——
A one-pot synthesis of secondary and tertiary amides from carboxylic acids and amines by using SOCl2 has been developed. Also when sterically hindered amines were used as the starting materials, excellent yields of the corresponding amides were obtained. The amidation of N-protected α-amino acids with secondary amines proceeds effectively with good yields. The process works well also in the presence