<i>N</i>-Difluoromethylthiophthalimide: A Shelf-Stable, Electrophilic Reagent for Difluoromethylthiolation
作者:Dianhu Zhu、Yang Gu、Long Lu、Qilong Shen
DOI:10.1021/jacs.5b03170
日期:2015.8.26
A new, electrophilic difluoromethylthiolating reagent N-difluoromethylthiophthalimide 3 was developed. Reagent 3 can be readily synthesized in four steps from easily available starting materials phthalimide and TMSCF2H. N-difluoromethylthiophthalimide 3 is a powerful electrophilic difluoromethylthiolating reagent that allows the difluoromethylthiolation of a wide range of nucleophiles including aryl/vinyl
On the basis of our recently reported aniline aqueous borylation, molecular diversity was achieved in a one-pot process by combining other reactions such as esterification, Suzuki-Miyaura coupling, hydrogenolysis, or Petasis borono-Mannich.
An Umpolung Approach for the Chemoselective Arylation of Selenocysteine in Unprotected Peptides
作者:Daniel T. Cohen、Chi Zhang、Bradley L. Pentelute、Stephen L. Buchwald
DOI:10.1021/jacs.5b05447
日期:2015.8.12
Herein we report an umpolung strategy for the bioconjugation of selenocysteine in unprotected peptides. This mild and operationally simple approach takes advantage of the electrophilic character of an oxidized selenocysteine (Se-S bond) to react with a nucleophilic arylboronic acid to provide the arylated selenocysteine within hours. This reaction is amenable to a wide range of boronic acids with different biorelevant functional groups and is unique to selenocysteine. Experimental evidence indicates that under oxidative conditions the arylated derivatives are more stable than the corresponding alkylated selenocysteine.