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
N-(4-Nitrophenylsulfonyl)- and N-(Fluorenylmethoxycarbonyl)-N-ethyl Amino Acid Methyl Esters - A Practical Approach
作者:Emilia Lucia Belsito、Rosaria De Marco、Maria Luisa Di Gioia、Angelo Liguori、Francesca Perri、Maria Caterina Viscomi
DOI:10.1002/ejoc.201000256
日期:2010.8
An efficient one-pot preparation of N-ethyl-N-4-nitrophenylsulfonyl (nosyl) aminoacid methyl esters was accomplished by a simple N-ethylation reaction by using triethyloxonium tetrafluoroborate in the presence of N,N-diisopropylethylamine. The N-ethylated aminoacid methyl esters are obtained with total retention of stereochemistry at the original chiral centers. To further broaden the scope of this
Design and Synthesis of Novel Helix Mimetics Based on the Covalent H-Bond Replacement and Amide Surrogate
作者:Junyang Liu、Shoubin Tang、Jia-Lei Yan、Tao Ye
DOI:10.3390/molecules28020780
日期:——
A novel hydrogen bond surrogate-based (HBS) α-helixmimetic was designed by the combination of covalent H-bond replacement and the use of an ether linkage to substitute an amide bond within a short peptide sequence. The new helix template could be placed in position other than the N-terminus of a short peptide, and the CD studies demonstrate that the template adopts stable conformations in aqueous
通过结合共价氢键取代和使用醚键取代短肽序列中的酰胺键,设计了一种新型的基于氢键替代物 (HBS) 的 α-螺旋模拟物。新的螺旋模板可以放置在短肽的 N 末端以外的位置,并且 CD 研究表明该模板在异常高温的水性缓冲液中采用稳定的构象。