The thermal cyclization of 3,4-diphenylbuta-1,3-dienyl isocyanates 1, generated in situ from the corresponding azides, was investigated using iodine as a catalyst. Diphenylpyridinones 2, phenylnaphthalenes 3, and indenes 4 were produced via intramolecular ring closure. The nature of the substituents on the phenyl rings was found to be crucial to the distribution of cyclized products 2-4. The mechanism of the reaction is also discussed.

1) Southern Luzon shows larger but fewer raindrops compared to neighboring countries.2) Four R(Z) relations were able to reduce radar-retrieved rainfall bias by up to 61%3) R(KDP) performed the best by a huge margin in terms of error statistics

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