in the oxidation of lactams moving from dimethyl dioxirane (DDO) to methyl(trifluoromethyl)dioxirane (TFDO). A physical organic chemistry study, which combines the oxidation with two other dioxiranes methyl(fluoromethyl)dioxirane, MFDO, and methyl(difluoromethyl)dioxirane, DFDO, with computational studies, points to a diverse ability of the dioxiranes to either stabilize the homo or the heterolytic
Design, Synthesis, and Biochemical Evaluation of <i>N</i>-Substituted Maleimides as Inhibitors of Prostaglandin Endoperoxide Synthases
作者:Amit S. Kalgutkar、Brenda C. Crews、Lawrence J. Marnett
DOI:10.1021/jm950872p
日期:1996.1.1
N-(Carboxyalkyl)maleimides are rapid as well as time-dependent inhibitors of prostaglandin endoperoxide synthase (PGHS). The corresponding N-alkylmaleimides were only time-dependent inactivators of PGHS, suggesting that the carboxylate is critical for rapid inhibition. Several N-substituted maleimide analogs containing structural features similar to those of the nonsteroidal anti-inflammatory drug
organocatalytic Beckmannrearrangement of ketoximes into amides has been realized by the catalytic use of cyanuric chloride. Furthermore, acids such as HCl and ZnCl2 are effective as cocatalysts with cyanuric chloride. For example, azacyclotridecan-2-one, which is synthetically useful as a starting material for nylon-12, was prepared in quantitative yield by the Beckmannrearrangement of cyclododecanone
Compounds of formula (I)
and pharmaceutically acceptable salts thereof, wherein R
1
, R
2
, R
3
, R
4
, L
1
and G
1
are as defined in the specification, are useful in treating conditions or disorders prevented by or ameliorated by positive allosteric modulation of the γ-aminobutyric acid B (GABA-B) receptor. Methods for making the compounds are described. Also described are pharmaceutical compositions of compounds of formula (I), and methods for using such compounds and compositions.
Synthesis of Cyclic Peptide Mimetics by the Successive Ring Expansion of Lactams
作者:Thomas C. Stephens、Mahendar Lodi、Andrew M. Steer、Yun Lin、Matthew T. Gill、William P. Unsworth
DOI:10.1002/chem.201703316
日期:2017.9.27
successive ring‐expansion protocol is reported that enables the controlled insertion of natural and non‐natural amino acid fragments into lactams. Amino acids can be installed into macrocycles via an operationally simple and scalable iterative procedure, without the need for high dilution. This method is expected to be of broad utility, especially for the synthesis of medicinally important cyclic peptide