Dichloroacetophenone Derivatives: A Class of Bioconjugation Reagents for Disulfide Bridging
摘要:
A mild and biocompatible method for the construction of disulfide bridging in peptides using dichloroacetophenone derivatives is developed. This method is highly selective (chemo, diastereo, regio, etc.) and atom economic and works under biocompatible reaction conditions (metal-free, water, pH 7, rt, etc.).
Zincke; Gerland, Chemische Berichte, 1888, vol. 21, p. 2392
作者:Zincke、Gerland
DOI:——
日期:——
Reactivity of in situ generated dihalomethyllithium towards dicarboxylic acid diesters and lactones: Synthetic applications
作者:José Barluenga、Luján Llavona、Miguel Yus、José M Concellón
DOI:10.1016/s0040-4020(01)81943-8
日期:1991.9
The reaction of dicarboxylic acid diesters 1, with in situ generated dihalomethyllithium (1:1.4 molar ratio) at -78-degrees-C leads, after hydrolysis, to the corresponding dihalomethylketoesters 3. The same process using an excess of the carbenoid (1:4 molar ratio) yields the expected tetrahalodiketones 5. The reaction of these carbenoids with gamma- and delta-lactones 6 at -78-degrees-C yields, after hydrolysis, 2-(dihalomethyl) gamma- or delta-lactols 7 or 8, respectively. The reaction of lactols 7 or 8 with triethylsilane or allyltrimethylsilane in the presence of BF3.OEt2 affords the corresponding substituted tetrahydrofurans or pyrans 10 or 12. The use of epsilon-caprolactone as starting material in the reaction with dihalomethyllithium leads to the corresponding 1,1-dihalo-7-hydroxy-2-heptanones.
Dichloroacetophenone Derivatives: A Class of Bioconjugation Reagents for Disulfide Bridging
A mild and biocompatible method for the construction of disulfide bridging in peptides using dichloroacetophenone derivatives is developed. This method is highly selective (chemo, diastereo, regio, etc.) and atom economic and works under biocompatible reaction conditions (metal-free, water, pH 7, rt, etc.).
Metal-Free Synthesis of 4-Chloroisocoumarins by TMSCl-Catalyzed NCS-Induced Chlorinative Annulation of 2-Alkynylaryloate Esters
4-Chloroisocoumarins can be conveniently prepared from 2-alkynylaryloate esters via the activation of alkynes by electrophilic chlorine, generated in situ from N-chlorosuccinimide (NCS) in the presence of 10 mol % trimethylsilyl chloride (TMSCl), which leads to 6-endo-dig-selective chlorinative annulation to give the desired products in moderate to quantitative yields. The procedure employs readily