Intramolecular Photoredox Reaction of Naphthoquinone Derivatives

Abstract

Photoinduced intramolecular redox reaction of naphthoquinone derivatives is described, enabling C–H bond oxygenation at the α-position of the quinone nucleus and the quinone reduction under photoirradiation. The substrate scope and mechanistic insight are reported.

Key words

naphthoquinone - photochemistry - redox reaction - cyclization - C–H bond functionalization

• References and Notes

• 1 Current address: School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachoji, Tokyo, 192-0392, Japan.
• 2 Kitamura K. Maezawa Y. Ando Y. Kusumi T. Matsumoto T. Suzuki K. Angew. Chem. Int. Ed. 2014; 53: 1262
• 3 Séquin U. Prog. Chem. Org. Nat. Prod. 1986; 50: 57

For photoinduced degradation of the pluramycins, see:
• 4a Fredenhagen A. Séquin U. J. Antibiot. 1985; 38: 236
• 4b Fredenhagen A. Séquin U. Helv. Chim. Acta 1985; 68: 391

For photoreactions of quinones in the presence of O₂, see:
• 5a Yates P. Mackay AC. Garneau FX. Tetrahedron Lett. 1968; 9: 5389
• 5b Kusumi T. Kishi T. Kakisawa H. Kinoshita T. J. Chem. Soc., Perkin Trans. 1 1976; 1716
• 5c Oka M. Konishi M. Oki T. Ohashi M. Tetrahedron Lett. 1990; 31: 7473
• 5d Krohn K. Ballwanz F. Baltus W. Liebigs Ann. Chem. 1993; 911
• 6 Analytical Data for 3a R_f = 0.58 (hexane–EtOAc, 1:2). ¹H NMR (600 MHz, CDCl₃): δ = 1.71–1.78 (m, 1 H), 1.84–1.95 (m, 2 H), 1.99–2.06 (m, 1 H), 2.07 (td, 1 H, J = 13.5, 4.1 Hz), 2.17 (qt, 1 H, J = 13.5, 4.0 Hz), 3.91–3.98 (m, 1 H), 4.04 (s, 3 H), 4.22–4.31 (m, 1 H), 6.63 (d, 1 H, J = 7.9 Hz), 6.75 (d, 1 H, J = 7.9 Hz), 6.79 (d, 1 H, J = 7.5 Hz), 7.21 (d, 1 H, J = 7.5 Hz), 7.52 (s, 1 H, OH). ¹³C NMR (150 MHz, CDCl₃): δ = 19.5, 24.7, 34.5, 56.2, 64.4, 103.0, 106.0, 110.9, 112.7, 113.1, 117.9, 129.1, 133.8, 145.5, 150.0, 155.7. IR (neat): 3485, 3012, 2946, 2882, 2840, 1645, 1611, 1506, 1473, 1423, 1364, 1262, 1231, 1128, 1108, 1070, 1030, 934, 902, 864, 852, 818, 798, 769, 663 cm^–1. HRMS (ESI-TOF): m/z calcd for C₁₆H₁₇O₄ [M + H]⁺: m/z = 273.1121; found: 273.1112.
• 7a Baldwin JE. Brown JE. J. Chem. Soc., Chem. Commun. 1969; 167
• 7b Ferreira MA. King TJ. Ali S. Thomson RH. J. Chem. Soc., Perkin Trans. 1 1980; 249
• 7c Mahoney NE. Chan BG. J. Nat. Prod. 1988; 51: 374
• 7d Hangarter M.-A. Hörmann A. Kamdzhilov Y. Wirz J. Photchem. Photobiol. Sci. 2003; 2: 524
• 8a Edwards OE. Ho P.-T. Can. J. Chem. 1978; 56: 733
• 8b Thommen C. Jana CK. Neuburger M. Gademann K. Org. Lett. 2013; 15: 1390

For related photoredox reactions of anthraquinones with electron transfer, see:
• 9a Smart RP. Peelen TJ. Blankespoor RL. Ward DL. J. Am. Chem. Soc. 1997; 119: 461
• 9b Blankespoor RL. Smart RP. Batts ED. Kiste AA. Lew RE. Vliet ME. V. J. Org. Chem. 1995; 60: 6852
• 10a Norrish RG. W. Appleyard ME. S. J. Chem. Soc. 1934; 874
• 10b Bamford CH. Norrish RG. W. J. Chem. Soc. 1935; 1504
• 10c Norrish RG. W. Bamford CH. Nature (London, U.K.) 1936; 138: 1016

For a review, see:
• 10d Scaiano JC. Lissi EA. Encina MV. Rev. Chem. Intermed. 1978; 2: 139
• 11a Wagner PJ. Zepp RG. J. Am. Chem. Soc. 1972; 94: 287
• 11b Wagner PJ. Kelso PA. Zepp RG. J. Am. Chem. Soc. 1972; 94: 7480
• 11c Wagner PJ. Acc. Chem. Res. 1971; 4: 168
• 12 For related photoredox reactions of α-oxoamides through zwitterion and the substituent effect, see: Aoyama H. Sakamoto M. Kuwabara K. Yoshida K. Omote Y. J. Am. Chem. Soc. 1983; 105: 1958
• 13 All the structures of products 3 were carefully verified by extensive 2D NMR spectroscopy. For 3d and 3f, single-crystal X-ray diffraction analyses were carried out (Figure 2).
• 14 CCDC-1522584 (3d) and CCDC-1522586 (3f) contain the supplementary crystallographic data for this paper. The data can be obtained free of charge from The Cambridge Crystallographic Data Centre (CCDC) via www.ccdc.cam.ac.uk/getstructures.
• 15 Aldehyde 1b generated from 1c was immediately oxidized to the naphthoquinone 2b by CAN.
• 16 In both cases, intractable mixtures of unidentified products were obtained, in which no cyclized products were identified.
• 17 Luo Y.-R. CRC Handbook of Bond Dissociation Energies in Organic Compounds. CRC Press; New York: 2003
• 18 The initial hydrogen abstraction of 2j may already be difficult. It is known that the excited carbonyl group is electrophilic, and the rate of γ-hydrogen abstraction becomes slower when an electron-withdrawing group is present at the γ-position. See: Wagner PJ. Kemppainen AE. J. Am. Chem. Soc. 1972; 94: 7495
• 19a de Meijere A. Angew. Chem., Int. Ed. Engl. 1979; 18: 809
• 19b Olah GA. Prakash GK. S. Sommer J. In Superacids . John Wiley and Sons; New York: 1985: 95-98
20
This result may be no wonder in view of that the ring opening of cyclopropylmethyl radical with a phenyl group is reversible in favor of the closed form (Scheme 7):
• a Halgren TA. Roberts JD. Horner JH. Martinez FN. Tronche C. Newcomb M. J. Am. Chem. Soc. 2000; 122: 2988
• b Bowry VW. Lusztyk J. Ingold KU. J. Chem. Soc., Chem. Commun. 1990; 923
• c Masnovi J. Samsel EG. Bullock RM. J. Chem. Soc., Chem. Commun. 1989; 1044
• 21 Bach T. Hehn JP. Angew. Chem. Int. Ed. 2011; 50: 1000