10.1002/adsc.201900334
Advanced Synthesis & Catalysis
subsequent radical coupling with HO· forms the final
product 2a, accompanied by releasing phenol. On the
other hand, when R3 equals to bulky group instead of
hydrogen, the neighboring group participation
overwhelms the previous pathway, and enables [A’]
Acknowledgements
This project is supported by the Fundamental Research Funds
for the Central Universities (NAU Grant Nos. KYDZ201904,
KJQN201719), the Qing-Lan Project of Jiangsu Provincial
Department of Education and the “333 High Level Talent
Project” of Jiangsu Province.
to deliver
a
five-membered intermediate [F].
Reversible ring-opening gives a cation [G], and an
intermediate [H] is subsequently obtained from the
reversible radical addition of HO· to [G]. The
existence of intermediate [H] was verified by BHT
inhibition experiment, with a key cation [H’] detected
by HR-MS (see details in S.I., page S10-11). β-
Scission of [H] releases diphenylphosphinic acid and
a radical cation [I], which captures hydroxyl radical
to finalize 3a after releasing a proton. Togni’s reagent
II is supposed to consume diphenylphosphinic acid
thus accelerates the rate-determine step (RDS) from
[H] to [I].
References and Notes
[1] For selected reviews: a) J.-P. Corbet, G. Mignani, Chem. Rev.
2006, 106, 2651; b) J. A. Labinger, J. E. Bercaw, Nature,
2002, 417, 507; c) T. Gensch, M. N. Hopkinson, F. Glorius, J.
Wencel-Delord, Chem. Soc. Rev. 2016, 45, 2900; d) L.
Souillart, N. Cramer, Chem. Rev. 2015, 115, 9410; e) G.
Fumagalli, S. Santon, J. F. Bower, Chem. Rev. 2017, 117,
9404; f) T.-Y. Luh, M.-K. Leung, K.-T. Wong, Chem. Rev.
2000, 100, 3187; g) N. J. Turner, Chem. Rev. 2011, 111,
4073; h) K. Ouyang, W. Hao, W.-X. Zhang, Z. Xi, Chem.
Rev. 2015, 115, 12045.
[2] a) P. E. Garrou, Chem. Rev. 1985, 85, 171; b) A. W. Parkins,
Chem. Rev. 2006, 250, 449; c) L. Wang, H. Chen, Z. Duan,
Chem. Asian J. 2018, 13, 2164; d) K. Jia, J. Li, Y. Chen,
Chem. Eur. J. 2018, 24, 3174.
In summary, we have revealed a novel strategy on
high regioselective cleavage of C(sp2)-P(O) bonds
with the combination of I2/TBHP. The substituent-
dependent cleavage of multi-substituted allenyl-
phosphine oxides resulted in divergent formation of
4-iodo-2-phenyl-5H-1,2-oxaphosphole 2-oxide and α-
iodo-enone derivatives in good to excellent yields,
respectively. This strategy features operational
simplicity, metal-free manner, and expands the
portfolio of organophosphorus chemistry in selective
bond cleavage.
[3] For selected examples on C-P(III) cleavage, see: a) F. Y.
Kwong, K. S. Chan, Organometallics 2000, 19, 2058; b) F.
Y. Kwong, K. S. Chan, Chem. Commun. 2000, 1069; c) J.
Cao, X. Huang, L. Wu, Chem. Commun. 2013, 49, 7747; d)
K. Baba, M. Tobisu, N. Chatani, Angew. Chem. Int. Ed. 2013,
52, 11892; e) K. Baba, M. Tobisu, N. Chatani, Org. Lett.
2015, 17, 70; f) H. Zhou, J. Li, H. Yang, C. Xia, G. Jiang,
Org. Lett. 2015, 17, 4628; g) Y. Zhou, Z. Gan, B. Su, J. Z.
Duan, F. Mathey, Org. Lett. 2015, 17, 5722. h) P. M. Scheetz,
D. S. Glueck, A. L. Rheingold, Organometallics, 2017, 36,
3387; i) R. Yu, X. Chen, S. F. Martin, Z. Wang, Org. Lett.
2017, 19, 1808; j) Z. Lian, B. N. Bhawal, P. Yu, B. Morandi,
Science, 2017, 356, 1059.
[4] a) D. E. C. Corbridge. Phosphorus: An Outline of its
Chemistry, Biochemistry and Technology, 4th ed.; Elsevier:
Amsterdam, 1990; b) G. P. Horsman, D. L. Zechel, Chem.
Rev. 2017, 117, 5704.
Experimental Section
General Procedures for the C(sp2)-P(O) Bond
Cleavage of Allenylphosphine Oxides.
[5] a) K. C. K. Swamy, M. Anitha, S. Debnath, M. Shankar,
Pure Appl. Chem. 2019, DOI: 10.1515/pac-2018-1111; b) S.
V. Lozovskiy, A. Y. Ivanov, A. S. Bogachenkov, A. V.
Vasilyev, ChemistrySelect, 2017, 2, 4505; c) A. S.
Bogachenkov, A. V. Dogadina, I. A. Boyarskaya, V. P.
Boyarskiy, A. V. Vasilyev, Org. Biomol. Chem. 2016, 14,
1370; d) N. Xin, S. Ma, Eur. J. Org. Chem. 2012, 3806; e) F.
Yu, X. Lian, J. Zhao, Y. Yu, S. Ma, J. Org. Chem. 2009, 74,
3, 1130; f) H. Guo, R. Qian, Y. Guo, S. Ma, J. Org. Chem.
2008, 73, 7934; g) M. Chakravarty, N. N. B. Kumar, K. V.
Sajna, K. C. K. Swamy, Eur. J. Org. Chem. 2008, 4500; h) F.
Yu, X. Lian, S. Ma, Org. Lett. 2007, 9, 1703; i) R. S.
Macomber, I. Constantinides, G. Garrett, J. Org. Chem. 1985,
50, 4711; j) R. S. Macomber, G. A. Krudy, J. Org. Chem.
1983, 48, 1425; k) S. Braverman, D. Reisman, Tetrahedron
Lett. 1977, 18, 1753.
[6] a) A. Inoue, H. Shinokubo, K. Oshima, J. Am. Chem. Soc.
2003, 125, 1484; b) T. Mizuta, N. Tanaka, Y. Iwakuni, K.
Kubo, K. Miyoshi, Organometallics, 2009, 28, 2808; c) E. J.
Derrah, S. Ladeira, G. Bouhadir, K. Miqueu, D. Bourissou,
Chem. Commun. 2011, 47, 8611; d) K. Masuda, N. Sakiyama,
R. Tanaka, K. Noguchi, K. Tanaka, J. Am. Chem. Soc. 2011,
133, 6918; e) E. Lu, Y. Chen, J. Zhou, X. Leng,
Organometallics, 2012, 31, 4574; f) J. Zhu, M. Mao, H.-J. Ji,
J.-Y. Xu, L. Wu, Org. Lett. 2017, 19, 1946; g) L. Qiu, W. Hu,
D. Wu, Z. Duan, F. Mathey, Org. Lett. 2018, 20, 7821; h) K.
Wei, K. Luo, F. Liu, L. Wu, L.-Z. Wu, Org. Lett. 2019, 21,
(Ph)C-P(O) Cleavage: To a 5 mL flask was added
allenylphosphine oxides (R3=H) (0.2 mmol), I2 (50.8
mg, 0.2 mmol), TBHP (51.5 mg, 0.4 mmol) and 2 mL
CCl4. The reaction mixture was then heated to reflux
for 4 hrs until the complete consumption of starting
materials monitored by TLC. After all of the volatiles
were removed under vacuum, the crude product was
purified on flash chromatography (eluent: 1:1 (v/v) of
ethyl acetate/petroleum ether) to afford product as a
white solids.
(allene)C-P(O) Cleavage: To a 5 mL flask was
added allenylphosphine oxides (R3≠H) (0.2 mmol), I2
(50.8 mg, 0.2 mmol), TBHP (51.5 mg, 0.4 mmol),
Togni’s Reagent II (63.2 mg, 0.2 mmol) and 2 mL
CCl4. The reaction mixture was then heated to reflux
for 4 hrs until the complete consumption of starting
materials monitored by TLC. After all of the volatiles
were removed under vacuum, the crude product was
purified on flash chromatography (eluent: 1:100 (v/v)
of ethyl acetate/petroleum ether) to afford product as
a viscous pale purple oil.
5
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