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Please login or sign up for a free trial to access the full content. Method 15: Functionalization of Annulenes via Annulynes

DOI: 10.1055/sos-SD-045-00322

Nishinaga, T.Science of Synthesis, (201045423.

Two types of annulynes, 67[‌89‌] and 71,[‌90‌] generated by the dehydrohalogenation of 2-bromobicyclo[4.4.1]undeca-1,3,5,7,9-pentaene (66) and bromodimethyldihydropyrene 70, respectively, can be used for functionalization of annulenes. When annulyne 67 is generated with potassium tert-butoxide in the presence of tert-butyl alcohol or piperidine, both the 2- and 3-substituted derivatives 68 and 69, respectively, with the corresponding alkoxy or amino groups are obtained (Scheme 29). The DielsAlder reaction of 71 with furan gives the adduct 72. Subsequent deoxygenation produces an aromatic ring; this has been used in the construction of a wide variety of annulated dihydropyrene derivatives.[‌81‌,‌91‌‌94‌]

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