Direct C(sp³)−H Sulfonylation and Sulfuration Reactions of Isoquinoline‐1,3(2H,4H)‐diones under Metal‐free Conditions

Abstract

The first direct C(sp3)−H bond sulfonylation and sulfuration reactions of isoquinoline‐1,3‐(2H,4H)‐diones have been developed under transition‐metal‐free conditions. Using air as the sole oxidant, the C‐4 sulfonylated products of isoquinolones were synthesized using sulfinates as the sulfonating agents and NaI as an iodine source in AcOH/DMSO. The sulfuration reaction was realized for the first time using disulfides as sulfurating partners in a t‐BuOK/DMF catalytic system. Both procedures undergo a free radical reaction process with the advantages of high atom economy, green reaction conditions, readily accessible materials and broad substrate scope.

CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

“…Approaches to sulfonylation and sulfenylation of isoquinoline‐1,3‐diones were reported [213] . As a result, 4‐functionalized derivatives are obtained.…”

“…[212] Approaches to sulfonylation and sulfenylation of isoquinoline-1,3-diones were reported. [213] As a result, 4-functionalized derivatives are obtained. Aromatic and aliphatic sodium sulfinates are applied for NaImediated sulfonylation in AcOH/DMSO mixture at 80 °C.…”

Cobalt-promoted synthesis of sulfurated oxindoles via radical annulation of N-arylacrylamides with disulfides

“…Furthermore, a bromine- or iodine-initiated radical process usually suffers from a low selectivity of reactive sites and uncertain functionalized products, which may limit its utility in organic synthesis. 21 Owing to our continued interest in the construction of sulfur-containing organic compounds, 22 herein we report our recent development of a highly atom-economical and reactive site selective synthesis route to sulfurated oxindoles via a CoBr 2 -initiated/promoted radical annulation of N -arylacrylamides with disulfides (Scheme 1c).…”

Transition‐Metal Free C(sp3)−H Sulfonylation for the Synthesis of 2‐Sulfolmethyl Quinolines from 2‐Methylquinolines and Sulfonyl Hydrazides

“…[40] Similar methods have been reported successively in recent years, which provides a new pathway for CÀ H sulfonylation. [41] Therefore, it is highly necessary and urgent to exploit more convenient, eco-friendly and transition-metal-free synthesis methods for sulfones.…”