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Abstract Hydrophosphination using calcium compounds as catalysts under irradiation is described as a foray into s‐block photocatalysis. Transition‐metal compounds have been highly successful hydrophosphination catalysts under photochemical conditions, utilizing substrates previously considered inaccessible. A calcium hydrophosphination precatalyst, Ca(nacnac) (THF) (N(SiMe3)2) (1, nacnac = HC[(C(Me)N‐2,6‐iPr2C6H3)]2), reported by Barrett and Hill, as well as the presumed intermediate, Ca(nacnac) (THF) (PPh2) (2), and the Schlenk equilibrium product, Ca[N(SiMe3)2]2(THF)2(3) were screened under photochemical conditions with a range of unsaturated substrates including styrenic alkenes, Michael acceptors, and dienes with modest to excellent conversions, though unactivated alkenes were inaccessible. All compounds exhibit enhanced catalysis under irradiation by light emitting diode (LED)‐generated blue light. Nacnac‐supported compounds generate radicals as evidenced by Electron Paramagnetic Resonance (EPR) spectroscopy and radical trapping reactions, whereas unsupported calcium compounds are EPR silent and appear to undergo hydrophosphination akin to thermal reactions with these compounds. These results buttress the notion that photoactivation of π‐basic ligands is a broad phenomenon, extending beyond the d‐block, but like d‐block metals, consideration of ancillary ligands is essential to avoid radical reactivity.
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Metal‐Catalyzed Hydrophosphination
Abstract Organophosphines have garnered attention from many avenues ranging from agriculture to fine chemicals. One‐time use of phosphate resources has made sustainable use of phosphorus overall imperative. Hydrophosphination serves as an efficient method to selectively prepare P−C bonds, furnishing a range of phosphorus‐containing molecules while maximizing the efficient use of phosphorus. Since the first report in 1958, a wide array of catalysts have appeared for hydrophosphination, a reaction that is spontaneous in some instances. This review presents a representative view of the literature based on known catalysts through mid‐2022, highlighting extensions to unique substrates and advances in selectivity. While several excellent reviews have appeared for aspects of this transformation, this review is meant as a comprehensive guide to reported catalysts.
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- Award ID(s):
- 2101766
- PAR ID:
- 10384512
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- ChemCatChem
- Volume:
- 14
- Issue:
- 22
- ISSN:
- 1867-3880
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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