Solid-State Photocycloaddition Reactions between Di-2-Pyrones Tethered by Arylalkyl Chain and Benzophenones

Abstract:

Solid-state photocycloaddition reactions between di-2-pyrones (1a-d) with benzophenone (2a) gave the corresponding oxetane derivatives (3a-d; 1:2 adducts) with high site- and regioselectivity across the C5-C6 and C5′-C6′ double bonds in 1 via the triplet excited state of 2a. The reactions were inferred by MO methods to be initiated by electrostatic interaction between the C6 position of 1a-d and the carbonyl oxygen of 2a at their ground states, and the solid-state interaction may be enhanced by electron density at carbonyl oxygen of the triplet 2a. The transition state (TS) analysis of the [2+2] cycloaddition reactions also suggested some triplet complex, and the high regioselectivity. The hydrogen-bonding interaction between 2a and 1a-d and the triplet reaction mechanism were also explained by the IR analyses and the quenching experiments, respectively.

• Periodical: Advanced Materials Research (Volumes 396-398)
• Pages: 2467-2470
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.396-398.2467
• Online since: November 2011
• Authors: Wei Dong Wang, Tetsuro Shimo
• Keywords: [2+2] Cycloadducts, Benzophenone, Di-2-Pyrones, Solid-State Photocycloaddition Reactions

References

[1] Y. Ito, Synthesis 1998, 1 and references cited therein.

[2] Y. Ito and H. Fujita, Chem. Lett. (2000), p.288.

[3] K. Tanaka and F. Toda, Chem. Rev. Vol. 100 (2000), p.1025.

[4] H. Koshima, H. Kawanishu, M. Nagano, H. Yu, M. Shiro, T. Hosoya, H. Uekusa and Y. Ohashi, J. Org. Chem. Vol. 70 (2005), p.4490.

[5] T. Obata, T. Shimo, S. Yoshimoto, K. Somekawa and M. Kawaminami, Chem. Lett. (1999), p.181.

[6] T. Obata, T. Shimo, M. Yasutake, T. Shinmyozu and K. Somekawa, Tetrahedron Vol. 57 (2001), p.1531.

[7] T. Shimo, T. Uezono, T. Obata, M. Yasutake, T. Shinmyozu and K. Somekawa, Tetrahedron Vol. 58 (2002), P. 6111.

DOI: 10.1016/s0040-4020(02)00582-3

[8] T. Shimo and K. Somekawa: Organic Photochimistry and Photobiology (CRC Press, USA 2003).

[9] T. Shimo, R. Yamaguchi, Y. Odo and K. Somekawa, Heterocycles Vol. 63 (2004), p.1541.

[10] W. D. Wang, T. Shimo, T. Shinmyozu, T. Iwanaga and K. Somekawa, Heterocycles Vol. 68 (2006), p.1381.

[11] Y. Odo, T. Shimo, K. Hori and K. Somekawa, Bull. Chem. Soc., Jpn. Vol. 77 (2004), p.1209.

[12] H. I. Omar., T. Shimo and K. Somekawa, J. Mol. Struct. (Theochem) Vol. 763 (2006), p.115.