Copper-catalyzed oxidative sulfenylation and alkylation of indolin-2-ones for direct construction of sulfur-substituted quaternary carbons

Abstract

The selective functionalization of ubiquitous C(sp³)–H bonds for constructing complex molecules is a highly sought-after method in academia as well as the chemical industry. In particular, it is rather challenging to install two different kinds of substituent groups into one reaction site in a one-pot process. To aid in this effort, we have developed a one-pot reaction for the construction of S-substituted quaternary carbon centers starting from secondary C(sp³)–H substrates. A sulfenylation and alkylation procedure catalyzed by simple copper salts has been established. It provides a rapid access to C3-alkylated 3-thioxyindolin-2-ones from abundant feedstock chemicals and features operational simplicity, broad substrate scope and good functional group compatibility.