Selective palladium-catalyzed cocyclotrimerization of arynes with dimethyl acetylenedicarboxylate: A versatile method for the synthesis of polycyclic aromatic …

…, D Pérez, E Guitián, L Castedo

Index: Pena; Perez; Guitian; Castedo Journal of Organic Chemistry, 2000 , vol. 65, # 21 p. 6944 - 6950

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Citation Number: 124

Abstract

Benzyne (1a) and the substituted derivatives 4, 5-difluorobenzyne (1b) and 3- methoxybenzyne (2) undergo chemoselective palladium-catalyzed [2+ 2+ 2]- cocyclotrimerization with dimethyl acetylenedicarboxylate (DMAD) to afford the corresponding phenanthrenes and/or naphthalenes. The major products are phenanthrenes if Pd (PPh3) 4 is used as the catalyst, naphthalenes if Pd2 (dba) 3 is used. When the ...