Visible light photocatalytic cross-coupling and addition reactions of arylalkynes with perfluoroalkyl iodides

Abstract

Visible light photocatalytic cross-coupling and addition reactions of arylalkynes with perfluoroalkyl iodides have been developed. Through slight modification of the reaction conditions, reactions that are selective for the preparation of...

Rose Bengal-photocatalyzed perfluorohexylation reactions of organic substrates in water. Applications to late-stage syntheses

“…When phenylacetylene was used as substrate, product 4 was obtained in 78% isolated yield, exclusively in a E configuration. Product 4 had previously been obtained [24] in 81% yield through the Ir-photocatalyzed reaction in DCM:H 2 O, as a mixture of the E:Z stereoisomers in a 86:14 isomeric ratio.…”

“…For the photocatalyzed reactions of alkenes and alkynes, products derived from the atom transfer radical addition (ATRA) pathway are obtained, and in the case of alkynes, exclusively as E-stereoisomers. It is of note that the current protocol is the first report on a photocatalyzed ATRA reaction in water alone, since other informed photocatalyzed methodologies utilized mixtures of water with organic solvents [24,28,29], thus rendering the current syntheses superior to other reported methodologies [24,31].…”

“…However, a vast majority of photocatalyzed perfluoroalkylation transformations of organic substrates are carried out in MeCN or DMSO, or mixtures of these latter solvents with MeOH or acetone [9,18]. In particular, a few visible light photocatalyzed fluoroalkylation reactions of organic substrates in aqueous media have recently been reported [17,[19][20][21][22][23][24][25][26], and some are illustrated in Scheme 1. Although the use of aqueous organic mixtures significantly diminishes the environmental impact of the overall strategy, the ideal allwater medium where organic photocatalysts, substrates, and perfluoroalkyl group sources could perform the fluoroalkylation reactions of organic substrates remains fleeting.…”

“…Among the photocatalyzed fluoroalkylation strategies reported in aqueous media, the reactions of olefins [27] and alkynes employing polypyridyl complexes of Ir as photocatalysts [19,21,23,24,28], and the Umemoto reagent [21] (Scheme 1B) or perfluoroalkyl iodides [24,28,29] (Scheme 1A, C, D) as sources of fluoroalkyl radicals have been informed. On the other hand, for the photocatalyzed perfluoroalkylation of aromatic substrates, examples employing tetrabutylammonium decatungstate (TBADT) as photocatalyst in conjunction with the Langlois reagent (Scheme 1E) as CF 3 radical source [25], or more recently the dyad vitamin B12 and Rose Bengal as photocatalysts in alliance with perfluoroalkyl bromides as fluoroalkyl radical sources [17], have been reported in aqueous media or water, respectively (Scheme 1F).…”

Recent Advances in Photoinduced Perfluoroalkylation Using Perfluoroalkyl Halides as the Radical Precursors

“…In 2020, Ko and co-workers 70 reported a photoinduced, Ir-catalyzed Sonogashira-type coupling of arylalkynes with perfluoroalkyl iodides, leading to the C-H perfluoroalkylation of terminal alkynes (Scheme 42). The photoredox conditions proved to be compatible with various alkynes and perfluoroalkyl iodides, such as C 4 F 9 I, C 6 F 13 I, and C 8 F 17 I.…”