Organic Letters
ORCID
Letter
(10) For reports on hypervalent iodine(III)-mediated decarboxylation
in which the reaction is supposed to proceed through a radical pathway
with photoactivation, see: (a) Concepcion, J. I.; Francisco, C. G.; Freire,
R.; Hernandez, R.; Salazar, J. A.; Suarez, E. J. Org. Chem. 1986, 51, 402.
(b) Francisco, C. G.; Gonzalez, C. C.; Suarez, E. Tetrahedron Lett. 1997,
38, 4141. (c) Boto, A.; Hernandez, R.; Suarez, E. Tetrahedron Lett.
1999, 40, 5945. (d) Boto, A.; Hernandez, R.; Suarez, E. J. Org. Chem.
2000, 65, 4930. (e) Boto, A.; Hernandez, R.; Suarez, E. Tetrahedron
Lett. 2000, 41, 2495. (f) Kiyokawa, K.; Watanabe, T.; Fra, L.; Kojima,
T.; Minakata, S. J. Org. Chem. 2017, 82, 11711. (g) Kiyokawa, K.;
Okumatsu, D.; Minakata, S. Beilstein J. Org. Chem. 2018, 14, 1046.
(11) There are only three reports on hypervalent iodine(III)-
mediated decarboxylation in which the reaction is supposed to proceed
through an ionic pathway without photoactivation; see: (a) Vaidyana-
than, K.; Venkatasubramanian, N. Curr. Sci. 1970, 233. (b) Moriarty, R.
M.; Gupta, S. C.; Hu, H.; Berenschot, D. R.; White, K. B. J. Am. Chem.
Soc. 1981, 103, 686. (c) Kiyokawa, K.; Yahata, S.; Kojima, T.; Minakata,
S. Org. Lett. 2014, 16, 4646.
(12) For recent reports on hypervalent iodine(III)-mediated oxidative
transformations, see: (a) Mizar, P.; Wirth, T. Angew. Chem., Int. Ed.
2014, 53, 5993. (b) Moteki, S. A.; Usui, A.; Selvakumar, S.; Zhang, T.;
Maruoka, K. Angew. Chem., Int. Ed. 2014, 53, 11060. (c) Banik, S. M.;
Medley, J. W.; Jacobsen, E. N. Science 2016, 353, 51. (d) Uyanik, M.;
Sasakura, N.; Mizuno, M.; Ishihara, K. ACS Catal. 2017, 7, 872.
Notes
́
́
́
́
́
́
́
The authors declare no competing financial interest.
́
́
́
́
ACKNOWLEDGMENTS
■
This work was supported by JSPS KAKENHI, Grant Nos.
JP16H06384 and JP18K14865. We are grateful to the Japan
Science Society for the Sasakawa Scientific Research Grant. We
also thank the Society of Iodine Science for a research grant.
REFERENCES
■
(1) For selected reviews on decarboxylative functionalization of
carboxylic acids, see: (a) Rodríguez, N.; Goossen, L. J. Chem. Soc. Rev.
2011, 40, 5030. (b) Xuan, J.; Zhang, Z.-G.; Xiao, W.-J. Angew. Chem.,
Int. Ed. 2015, 54, 15632. (c) Guo, L.-N.; Wang, H.; Duan, X.-H. Org.
Biomol. Chem. 2016, 14, 7380. (d) Liu, P.; Zhang, G.; Sun, P. Org.
̈
Biomol. Chem. 2016, 14, 10763. (e) Schwarz, J.; Konig, B. Green Chem.
2018, 20, 323.
(2) (a) Ragsdale, S. W. Chem. Rev. 2003, 103, 2333. (b) Jordan, F.;
Patel, H. ACS Catal. 2013, 3, 1601.
(e) Muniz, K.; Barreiro, L.; Romero, R. M.; Martínez, C. J. Am. Chem.
̃
(3) For radical-mediated decarboxylative amidation of α-ketoacid,
see: (a) Liu, J.; Liu, Q.; Yi, H.; Qin, C.; Bai, R.; Qi, X.; Lan, Y.; Lei, A.
Angew. Chem., Int. Ed. 2014, 53, 502. (b) Xu, W.-T.; Huang, B.; Dai, J.-
J.; Xu, J.; Xu, H.-J. Org. Lett. 2016, 18, 3114. (c) Xu, X.-L.; Xu, W.-T.;
Wu, J.-W.; He, J.-B.; Xu, H.-J. Org. Biomol. Chem. 2016, 14, 9970.
(4) For a review on KAHA ligation, see: Bode, J. W. Acc. Chem. Res.
2017, 50, 2104.
(5) For selected reports on KAHA ligation, see: (a) Bode, J. W.; Fox,
R. M.; Baucom, K. D. Angew. Chem., Int. Ed. 2006, 45, 1248.
(b) Carrillo, N.; Davalos, E. A.; Russak, J. A.; Bode, J. W. J. Am. Chem.
Soc. 2006, 128, 1452. (c) Ju, L.; Lippert, A. R.; Bode, J. W. J. Am. Chem.
Soc. 2008, 130, 4253.
(6) Bode and co-workers reported ester formation by KAHA ligation
with 5-oxaproline as a nucleophile; see: Wucherpfennig, T. G.;
Rohrbacher, F.; Pattabiraman, V. R.; Bode, J. W. Angew. Chem., Int.
Ed. 2014, 53, 12244.
(7) For other decarboxylative acylations using α-ketoacid, see:
(a) Sakamoto, Y.; Yoshioka, T.; Uematsu, T. J. Org. Chem. 1989, 54,
4449. (b) Fontana, F.; Minisci, F.; Barbosa, M. C. N.; Vismara, E. J. Org.
Chem. 1991, 56, 2866. (c) Pilepic, V.; Ursic, S. Tetrahedron Lett. 1994,
35, 7425. (d) Wang, C.; Wang, S.; Li, H.; Yan, J.; Chi, H.; Chen, X.;
Zhang, Z. Org. Biomol. Chem. 2014, 12, 1721. (e) Huang, H.; Zhang, G.;
Chen, Y. Angew. Chem., Int. Ed. 2015, 54, 7872. (f) Wang, P.-F.; Feng,
Y.-S.; Cheng, Z.-F.; Wu, Q.-M.; Wang, G.-Y.; Liu, L.-L.; Dai, J.-J.; Xu, J.;
Xu, H.-J. J. Org. Chem. 2015, 80, 9314. (g) Wang, G.-Z.; Shang, R.;
Cheng, W.-M.; Fu, Y. Org. Lett. 2015, 17, 4830. (h) Yan, K.; Yang, D.;
Wei, W.; Zhao, J.; Shuai, Y.; Tian, L.; Wang, H. Org. Biomol. Chem.
2015, 13, 7323. (i) Ji, W.; Tan, H.; Wang, M.; Li, P.; Wang, L. Chem.
Commun. 2016, 52, 1462. (j) Yang, S.; Tan, H.; Ji, W.; Zhang, X.; Li, P.;
Wang, L. Adv. Synth. Catal. 2017, 359, 443. (k) Pimpasri, C.;
Sumunnee, L.; Yotphan, S. Org. Biomol. Chem. 2017, 15, 4320.
(8) (a) Beebe, T. R.; Baldridge, R.; Beard, M.; Cooke, D.; DeFays, I.;
Hensley, V.; Hua, D.; Lao, J.-C.; McMillen, D.; Morris, D.; Noe, R.;
O’Bryan, E.; Spielberger, C.; Stolte, M.; Waller, J., Jr. J. Org. Chem. 1987,
52, 3165. (b) Padala, A. K.; Saikam, V.; Ali, A.; Ahmed, Q. N.
Tetrahedron 2015, 71, 9388. In the following literature, decarboxylative
esterification of α-ketoacids alcohols was described as a control
experiment; see: (c) Huang, X.; Li, X.; Zou, M.; Song, S.; Tang, C.;
Yuan, Y.; Jiao, N. J. Am. Chem. Soc. 2014, 136, 14858. (d) Ma, R.; He,
L.-N.; Liu, A.-H.; Song, Q.-W. Chem. Commun. 2016, 52, 2145.
(9) For selected reviews on hypervalent iodine(III) species, see:
(a) Kita, Y.; Dohi, T. Chem. Rec. 2015, 15, 886. (b) Li, Y.; Hari, D. P.;
Vita, M. V.; Waser, J. Angew. Chem., Int. Ed. 2016, 55, 4436.
(c) Yoshimura, A.; Zhdankin, V. V. Chem. Rev. 2016, 116, 3328.
Soc. 2017, 139, 4354. (f) Miyamoto, K.; Yamashita, J.; Narita, S.; Sakai,
Y.; Hirano, K.; Saito, T.; Wang, C.; Ochiai, M.; Uchiyama, M. Chem.
Commun. 2017, 53, 9781.
(13) While all decarboxylative esterifications were performed in the
dark, it was revealed that the reaction was not influenced by the
presence or absence of the shield from room light. Additionally, light
irradiation using a xenon lamp significantly decreased the yield of the
desired ester due to the decomposition of both substrates and reagents,
whereas the addition of a radical scavenger only slightly dropped the
yield of the ester. These results indicate that the reaction presumably
proceeds through not a radical but an ionic pathway. See the
(14) Iinuma, M.; Moriyama, K.; Togo, H. Eur. J. Org. Chem. 2014,
2014, 772.
(15) Haskali, M. B.; Telu, S.; Lee, Y.-S.; Morse, C. L.; Lu, S.; Pike, V.
W. J. Org. Chem. 2016, 81, 297.
(16) While compound 4f was stable enough to synthesize and store in
a normal manner, a nitro group on the para- and ortho-positions made
the hypervalent iodine (III) species more unstable.
́
̌
́
(17) (a) Valeur, E.; Bradley, M. Chem. Soc. Rev. 2009, 38, 606. (b) El-
Faham, A.; Albericio, F. Chem. Rev. 2011, 111, 6557.
(18) Lollar, C. T.; Krenek, K. M.; Bruemmer, K. J.; Lippert, A. R. Org.
Biomol. Chem. 2014, 12, 406.
(19) Dewick, P. M. Medicinal Natural Products: A Biosynthetic
Approach, 3rd ed.; John Wiley & Sons: Chichester, 2009; pp 247−298.
(20) He, W.-S.; Zhu, H.; Chen, Z.-Y. J. Agric. Food Chem. 2018, 66,
3047.
(21) Ligand exchange on a hypervalent iodine (III) atom is known to
be easy. Thus, there is a possibility that coordination of α-
ketocarboxylate to hypervalent iodine (III) initiates the nucleophilic
addition of alcohol to afford a tetrahedral intermediate. See ref 7e.
(22) In a precedent report on a simple decarboxylation of α-ketoacid
mediated by PhI(OAc)2, an intermediate similar to B2 was proposed.
However, the author did not provide any evidence on the mechanism.
See ref 11a.
(23) (a) Hamada, Y. Bioorg. Med. Chem. Lett. 2017, 27, 1627.
(b) Sinokrot, H.; Smerat, T.; Najjar, A.; Karaman, R. Molecules 2017,
22, 1736.
(d) Muniz, K. Acc. Chem. Res. 2018, 51, 1507.
̃
D
Org. Lett. XXXX, XXX, XXX−XXX