Naphthonitrile-alkene exciplexes. Use of tethered chromophores to probe geometric factors in exciplex formation and decay

Abstract

Sir:The aryl nitrile-olefm systems are interesting because they show exciplex fluorescence' as well as photoreactions. These allow Hamilton, Ontario, Canada U S 4Ml

One‐Step Synthesis of Benzotetra‐ and Benzopentacyclic Compounds through Intramolecular [2+3] Photocycloaddition of Alkenes to Naphthalene

“…[9] The related intramolecular photocycloaddition of 6 c was reported by McCullough et al to give two types of [2+2] photocycloadducts, 7 c and 8 c, with 7 c as the major product (Scheme 3). [4] We had previously studied the related reactions of 6 a-e and obtained products to which we originally assigned structures 7 a-e and 8 a-e, by analogy with the assignment of McCullough et al [5] We have found recently that the product ratios of both product types in the photoreactions of 6 a-e are dependent on additives and solvents. In addition, the major products 7 a-e gradually reverted to the starting compounds 6 a-e, but the minor products were stable under the reaction conditions.…”

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Photocycloaddition of unsaturated compounds to aromatic rings is a useful and convenient method for the construction of polycyclic compounds in organic synthesis. [1][2][3][4][5][6][7] In particular, the inter-and intramolecular metaphotocycloaddition of alkenes to benzene rings has been extensively developed from the synthetic and mechanistic points of view in recent decades. [1,2] Wender et al first reported the synthesis of natural products by using an intramolecular meta-photocycloaddition as a key step.

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One‐Step Synthesis of Benzotetra‐ and Benzopentacyclic Compounds through Intramolecular [2+3] Photocycloaddition of Alkenes to Naphthalene

“…[1][2][3][4][5][6][7] In particular, the inter-and intramolecular metaphotocycloaddition of alkenes to benzene rings has been extensively developed from the synthetic and mechanistic points of view in recent decades. [1][2][3][4][5][6][7] In particular, the inter-and intramolecular metaphotocycloaddition of alkenes to benzene rings has been extensively developed from the synthetic and mechanistic points of view in recent decades.…”

“…However, prolonged irradiation afforded 3 b as the sole product in a highly Scheme 1. [4] We had previously studied the related reactions of 6 a-e and obtained products to which we originally assigned structures 7 a-e and 8 a-e, by analogy with the assignment of McCullough et al [5] We have found recently that the product ratios of both product types in the photoreactions of 6 a-e are dependent on additives and solvents. Irradiation of isolated 2 b quickly gave 1 b; clearly, the [2+2] cycloaddition in this system is reversible.…”

“…[9] The related intramolecular photocycloaddition of 6 c was reported by McCullough et al to give two types of [2+2] photocycloadducts, 7 c and 8 c, with 7 c as the major product (Scheme 3). [4] We had previously studied the related reactions of 6 a-e and obtained products to which we originally assigned structures 7 a-e and 8 a-e, by analogy with the assignment of McCullough et al [5] We have found recently that the product ratios of both product types in the photoreactions of 6 a-e are dependent on additives and solvents. In addition, the major products 7 a-e gradually reverted to the starting compounds 6 a-e, but the minor products were stable under the reaction conditions.…”