Organic Letters
Letter
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(14) The phosphine ligands bearing with similar structure (less one
carbon) were applied as chiral organocatalysts for the asymmetric
catalysis. For details, see: (a) Xing, J.; Lei, Y.; Gao, Y.-N.; Shi, M.
PPh3-Catalyzed [3 + 2] Spiroannulation of 1C,3N-Bisnucleophiles
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t
(15) For the synthesis of BuOOSiMe3, please see the Supporting
Information. Fan, Y. L.; Shaw, R. G. Amine-Hydroperoxide Adducts.
Use in Synthesis of Silyl Alkyl Peroxides. J. Org. Chem. 1973, 38,
2410−2412.
(16) For the reaction of TMSCN with water, see the Supporting
Information.
(8) Fu, L.; Zhou, S.; Wan, X.; Chen, P.; Liu, G. Enantioselective
Trifluoromethylalkynylation of Alkenes via Copper-Catalyzed Radical
Relay. J. Am. Chem. Soc. 2018, 140, 10965−10969.
t
(17) The absorption band of pure BuOOSiMe2 locates at 282 nm;
for details, see SI.
(9) Although few phosphonate esters like R2P(O)SR′ and R2P(O)
SeR′ were reported to generate phosphinoyl radicals initiated by
Bu3SnH, these reagents were incompatible with the copper-catalyzed
radical relay process. For the examples of these reagents, see
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(19) For the alternative pathway, the benzylic radical is possibly
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Dhimane, A. L.; Fensterbank, L.; Lacote, E.; Malacria, M. Generation
oxidized to form carbocation, followed by tBuOOH attack to give 3a′.
of Phosphorus-Centered Radicals via Homolytic Substitution at
Sulfur. Org. Lett. 2007, 9, 1061−1063.
(10) (a) Gephart, R. T.; McMullin, C. L.; Sapiezynski, N. G.; Jang,
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(11) (a) Yang, B.; Yang, T.-T.; Li, X.-A.; Wang, J.-J.; Yang, S.-D. A
Mild, Selective Copper-Catalyzed Oxidative Phosphonation of α-
Amino Ketones. Org. Lett. 2013, 15, 5024−5027. (b) Zhang, P.;
Zhang, L.; Gao, Y.; Xu, J.; Fang, H.; Tang, G.; Zhao, Y. Copper-
catalyzed tandem phosphination− decarboxylation−oxidation of
alkynyl acids with H-phosphine oxides: a facile synthesis of β-
ketophosphine oxides. Chem. Commun. 2015, 51, 7839−7842.
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