title: Addition of heteroaromatics to alkylidenecyclopropanes catalyzed by palladium.
abstract: The reaction of heteroaromatics, such as furans, thiophenes, thiazoles, and pyrroles, with alkylidenecyclopropanes proceeded smoothly in the presence of palladium catalysts, producing the corresponding alpha-allylated products in good to high yields. For example, the reaction of 3-butylpentylidenecyclopropane (1a) with 2-methylfuran (2a), ethyl 2-thiophenecarboxylate (4a), 2-isobutylthiazole (6a), and 1-methylpyrrole (11b) gave the alpha-allylated products in 70%, 66%, 77%, and 30% yield, respectively. The reaction proceeded predominantly through distal bond cleavage. The order of reactivity of heteroaromatics toward 1a is as follows: furan > thiophene approximately thiazole (5-position) > thiazole (2-position) approximately pyrrole. This methodology provides a means for introducing an allylic group to various kinds of heteroaromatics under mild conditions.
authors: Department of Chemistry, Graduate School of Science, and Research Center for Organic Resources and Material Chemistry, Institute for Chemical Reaction Science, Tohoku University, Sendai 980-8578, Japan.
authors: Itaru
authors: I
authors: Nakamura
authors: Amal I
authors: AI
authors: Siriwardana
authors: Shinichi
authors: S
authors: Saito
authors: Yoshinori
authors: Y
authors: Yamamoto