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Abstract Visible‐light‐induced halide‐exchange between halide perovskite and organohalide solvents has been studied in which photoinduced electron transfer from CsPbBr3nanocrystals (NCs) to dihalomethane solvent molecules produces halide anions via reductive dissociation, followed by a spontaneous anion‐exchange. Photogenerated holes in this process are less focused. Here, for CsPbBr3in dibromomethane (DBM), we discover that Br radical (Br⋅) is a key intermediate resulting from the hole oxidation. We successfully trapped Br⋅ with reported methods and found that Br⋅ is continuously generated in DBM under visible light irradiation, hence imperative for catalytic reaction design. Continuous Br⋅ formation within this halide‐exchange process is active for photocatalytic [3+2] cycloaddition for vinylcyclopentane synthesis, a privileged scaffold in medicinal chemistry, with good yield and rationalized diastereoselectivity. The NC photocatalyst is highly recyclable due to Br‐based self‐healing, leading to a particularly economic and neat heterogeneous reaction where the solvent DBM also acts as a co‐catalyst in perovskite photocatalysis. Halide perovskites, notable for efficient solar energy conversion, are demonstrated as exceptional photocatalysts for Br radical‐mediated [3+2] cycloaddition. We envisage such perovskite‐induced Br radical strategy may serve as a powerful chemical tool for developing valuable halogen radical‐involved reactions.
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Radical Perfluoroalkylation Enabled by a Catalytically Generated Halogen Bonding Complex and Visible Light Irradiation
Exploiting charge-transfer complexes in visible light-promoted single-electron redox reactions is a promising route for opening novel synthetic pathways, and catalytic approaches to complex formation are critical for facilitating this chemistry. This report describes the use of a substituted hydroquinone catalyst to promote radical perfluoroalkylation reactions. Mechanistic studies indicate that the reaction is initiated through formation of a visible light-absorbing halogen bonding complex between the hydroquinone catalyst and the perfluoroalkyl halide radical precursor.
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- Award ID(s):
- 1847583
- PAR ID:
- 10329087
- Editor(s):
- Kozlowski, Marisa C.
- Date Published:
- Journal Name:
- Organic letters
- Volume:
- 24
- Issue:
- 1
- ISSN:
- 1523-7060
- Page Range / eLocation ID:
- 446 - 450
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/https://doi.org/10.1021/acs.orglett.1c04139
