Synthesis of novel polycyclic aromatic hydrocarbons by transannular

Synthesis of novel polycyclic aromatic hydrocarbons by transannular cyclization of dehydrobenzoannulenes Tobe Laboratory M 1 Yamane Hiroshi

~Introduction~ Polycyclic Aromatic Hydrocarbons (PAH) PAH・・・多環状芳香族化合物 picene K - Doped 20 K Superconducting materials Kubozono, Y. et al. Nature, 2010, 464, 76 -79. 9, 9’-bifluorenylidene Electron Acceptors of Lightweight Organic devices Wudl, F. et al. Angew. Chem. Int. Ed. 2009, 49, 532 -536.

~Introduction~ Reactivity of alkyne πbond σbond Bond energy : σbond > πbond(1) >πbond(2) (k. J/mol) 369 268 202 Alkyne has high reactivity

~Introduction~ Tandem Cyclization Reaction by Electrophile Tandem Cyclization・・・連続環化 Lutz, V. et al. Angew. Chem. Int. Ed. 2003, 42, 5757− 5760. Scheme 1. Tandem cyclization reaction by electrophilic Low selectivity and low yield 4

~Purpose of my reserch~ Motivation Noncyclic compounds Distance between acetylenes is loose ・Low selectivity ・Low yield Cyclic compounds Distance between acetylenes is fixed ・Improvement of selectivity ・Improvement of yield ・Induction of spontaneous reaction

~Purpose of my reserch~ Transannular cyclization for cyclic compounds Scheme 2. Transannular cyclization of cyclic compounds by several ways

Three-dimentional model of 1 Figure 1. Cariculated three-dimentional model of 1 (calculations are based on B 3 LYP/6 -31 G*)

Prediction of reaction of 1 with nucleophile Scheme 3. Predicted cyclization reaction of 1

Synthesis route of 1 Sceme 4. Synthesis route of 1

Prediction of reaction of 7 Scheme 5. Reaction of 7 passed through benzyne intermediate

Computational results for [2+4] diyne-yne cycloaddition ＋ 0. 0 kcal/mol TS 1 +36. 5 High potential Energy E -51. 4 reactive coordinate Aida A. et al. J. Org. Chem. 2011, 76, 9320 -9328.

Property of benzyne Overlap of each p orbital is little benzene benzyne sp 2 orbitals are conjugated Electrons are localized More destabilization Scheme 6. Diels-Alder reaction of benzyne and furan

Future work Scheme 8. Trapping of benzyne intermediate by furan

Conclusion • Acetylene-integrated 1 is designed. • After the synthesis of 1, 7 is considered generated via benzyne intermediates. • I will confirm the presence of a benzyne intermediate by furan.