Effects of the Linkage Length and Substituents on the Photocycloaddition of Bis(vinylnaphthyl)alkanes toward Naphthalenophanes
摘要:
Many naphtalenophanes, including a dicarbomethoxy-substituted one, a di-4-pyridyl-substituted one, and a bis(trimethylsilyl)-substituted one, were synthesized by applying intramolecular [2+2] photocycloaddition of α,ω-bis(1-vinylnaphthyl) alkanes. The effect of the linkage and substituents at the α and/or β positions of the vinyl groups was investigated concerning this photocycloaddition. From the results of the investigation, the limitation and scope of the photocycloaddition toward naphthalenophanes has been established.In addition to this preparative study, an anomalous transannular photoproduct, which was formed from cis, exo-1,2-ethano-syn-[2.3](1,4)naphthalenophane and analyzed by X-ray crystallography, was found to undergo thermal cycloreversion through diene and tetraene intermediates. The kinetics of this reversion were studied. Moreover, some obtained naphthalenophanes showed an interesting tendency to form 1 : 1 mixed crystals with small flat-shaped recrystallization solvents having donor substituents. This nature is also briefly reported.
Intramolecular [2+2] Photocycloaddition. 5. Synthetic Methods toward [2.<i>n</i>]-, [3.<i>n</i>]-, and [4.<i>n</i>]Naphthalenophane Skeletons by Using α,ω-Bis(vinylnaphthyl)alkanes
[2+2] Photocycloaddition, cationic cyclocodimerization, and reductive ring enlargement were developed for the syntheses of [2.n]-, [3.n]-, and [4.n]naphthalenophanes, respectively, from α,ω-bis(vinylnaphthyl)alkanes as a single starting material. Using the exclusive syn selectivity of the former two methods, the room required for the intraannular naphthalene-ring rotation in the ring system is determined.
1,3-bis(4-vinylnaphthyl)propane and 1-(4-vinylnaphthyl)-3-(-vinylphenyl)propane, were cyclocodimerized with indene to afford indenyl-substituted [3.3](1,4)naphthalenophanes and [3.3]paracyclo(1,4)naphthalenophanes.
Cationic cyclocodimerization. 3. Syntheses of [3.3]paracyclo(1,4)naphthalenophane and [3.3](1,4)naphthalenophane derivatives. Stereoselectivity governed by the structures of .alpha.-naphthylmethylcarbenium ion and 1-vinylnaphthyl moiety