Visible Light-Induced Highly Regioselective and Stereoselective Oxysulfonylation of Alkynes for the Synthesis of (E)-β-Phenoxy Vinylsulfones

Abstract

A highly efficient visible light-induced regioselective and stereoselective oxysulfonylation of alkynes with arylsulfonate phenol esters has been developed. This photocatalyst-and metal-free method proceeds smoothly under very mild conditions and exhibits a broad substrate scope, providing (E)-β-phenoxy vinylsulfones in moderate to excellent yields. Mechanistic studies indicated the involvement of an electron donor− acceptor complex-mediated radical process.

Photocatalytic iodosulfonylation of internal alkynes under green conditions

“…42 Zhang et al reported the violet (400 nm) light-induced synthesis of (E)-β-phenoxyvinylsulfones via an EDA complex-mediated radical reaction. 43 Using visible light, we, 44 Mutra et al, 45 and Gurawa et al 46 have recently shown that the photoinduced addition of RSO 2 I to internal alkynes in acetonitrile occurs with high yields and regio-and stereoselectivity. Such a reaction would represent in principle an ideal atom-saving process.…”

“…42 Zhang et al reported the violet (400 nm) light-induced synthesis of ( E )–β-phenoxyvinylsulfones via an EDA complex-mediated radical reaction. 43…”

Metal‐Free Visible‐light Mediated C−S Bond Formation

“…The reaction went smoothly in the absence of any photosensitizer and the reaction went via an electron donor‐acceptor complex‐mediated radical process (Scheme 14). [17a] As per the suggested mechanism, an intermolecular electron donor‐acceptor complex is formed between arylsulfonate phenol ester ( 23 ) and the enolate of DMA in the presence of a base. Next, as a result of visible‐light irradiation the excited EDA complex underwent an intracomplex single‐electron transfer (SET) to generate a radical anion ( A ) and α‐carbamoyl radical.…”

Trace water in a BF3·OEt2 system: a facile access to sulfinyl alkenylsulfones from alkynes and sodium sulfinates

“…5 Owing to the interest in its synthesis, 6 there are numerous synthetic methods for vinyl sulfone synthesis. 7 Usually, the difunctionalization of alkynes 8 can provide an efficient and direct way via the concomitant introduction of two different functional groups 9 (Scheme 1a). For instance, Tang's group 10 reported a direct disulfonylation reaction of terminal alkynes and sodium sulfinates with a Cu( i ) catalyst (Scheme 1b).…”