AgSbF₆-Mediated Selective Thiolation and Selenylation at C-4 Position of Isoquinolin-1(2H)-ones

Abstract

A new and facile AgSbF-mediated protocol for the construction of C-4 thiolated or selenylated isoquinolin-1(2 H)-ones via a radical pathway was established. This reaction proceeded efficiently with excellent regioselectivity, a broad substrate scope, and good functional group tolerance. A radical reaction mechanism involving thiyl radicals as key intermediates is proposed for the present transformation.

I2‐Promoted Direct C−H Sulfenylation of Isoquinolin‐1(2H)‐ones with Sulfonyl Chlorides

“…4‐( p ‐Tolylthio)isoquinolin‐1( 2H )‐one (4 aa) : [14d,19] Chromatography (EtOAc/petroleum ether=1 : 2), R f =0.3. Pink solid, yield: 79 %, m.p.…”

“…In 1988, Nagarajan [18] and co‐workers first reported the reaction of isoquinolin‐1(2 H )‐one derivative and p ‐nitrobenzenesulfonyl chloride in the presence of Et 3 N to give the sulfenylated product in very low yield (10 %), and speculated that the reaction involved an intermolecular reduction/oxidation process. Very recently, Zhu [19] developed a new AgSbF 6 ‐mediated regioselective deoxygenative C−H thiolation of isoquinolin‐1(2 H )‐ones with diphenyl disulfides (Scheme 1e). Despite this progress, metal‐free‐catalyzed direct C‐4 sulfenylation of isoquinolin‐1(2 H )‐ones has not yet been documented.…”

Comprehensive Overview of Progress in Functionalization of 2‐Pyridone and 2, 4 ‐Dihydroxy Pyridine: Key Constituents of Vital Natural Products

“…Zhu et al [167] . designed thiolation and selenylation of 2‐pyridones (193) with diaryl disulphides (194) in presence of AgSbF 6 (Scheme 60) .…”

“…Zhu et al [167] designed thiolation and selenylation of 2pyridones (193) with diaryl disulphides (194) in presence of AgSbF 6 (Scheme 60) . The reaction accounted for excellent regioselectivity, tolerated wide range of functional groups and was efficient with yields upto 99 % in presence of toluene as solvent.…”

A Palladium(0)‐Catalyzed C4 Site‐Selective C−H Difluoroalkylation of Isoquinolin‐1(2H)‐Ones

“…When isoquinolin‐1( 2H )‐one 1 was reacted with Br 2 , I 2 , NCS, TSCF 3 , ICI, HNO 3 or NFSI respectively, different substituents (−Br, −I, −Cl, −CF 3 , −NO 2 or −F) could be introduced at C4‐position (Scheme 1a) [19a–h] . Through a radical pathway, C‐4 thiolated isoquinolin‐1( 2H )‐ones were obtained by reacting 1 with diaryl disulfides (Scheme 1b) [19i–j] . The C4‐selective arylation or alkynylation of isoquinolin‐1( 2H )‐ones 1 was successfully achieved via an electrophilic palladation pathway (Scheme 1c) [19k] or an electrophilic alkynylation pathway (Scheme 1d) [19l–m] …”