An unusual domino reaction where the same furan α‐carbon atom reacts initially as a nucleophile and then as an electrophile is reported. In the presence of acid, N‐tosylfurfurylamines react with 2‐(tosylamino)benzyl alcohols to afford 2‐(2‐acylvinyl)indoles. The reaction proceeds by Friedel–Crafts alkylation at the C(2) atom of furan followed by acid‐catalyzed intramolecular nucleophilic attack of the ortho‐amino group onto the same carbon atom. The replacement of the tosylamino leaving group by phthalimide enables generation of a different type of indole yet allows the ambiphilic nature of C(2) to be retained. Both types of indoles were obtained when N‐furfurylbenzamides were employed.

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Synthesis of Indoles by Domino Reaction of 2-(Tosylamino)benzyl Alcohols withFurfurylamines: Two Opposite Reactivity Modes of the -Carbon of the Furan Ring in One Process. -The unusual domino reaction of substrates (I) with N-tosylfurfurylamine (II) produces indoles (III) via sequential Friedel-Crafts alkylation, Piancatelly-like intramolecular rearrangement, and aromatization. The specific feature of this reaction is the unusual behaviour of the furan -carbon atom, which reacts initially as a nucleophile and later as electrophile. Substitution of the tosylamino group in the furan side chain changes chemoselectivity of the reaction. -(UCHUSKIN*, M. G.; MOLODTSOVA, N. V.; LYSENKO, S. A.; STREL'NIKOV, V. N.; TRUSHKOV, I. V.; BUTIN, A. V.; Eur.

Furan Ring Opening-Indole Ring Closure: SnCl 2 -Induced Reductive Transformation of Difuryl(2-nitroaryl)methanes into 2-(2-Acylvinyl)indoles. -The reaction proceeds via reductive furan ring opening followed by indole ring closure. It is shown, that the corresponding bisthienylmethanes fail to undergo an analogous recyclization and are transformed into thienylaminomethanes (XIII). -(UCHUSKIN, M. G.; MOLODTSOVA, N. V.; ABAEV, V. T.; TRUSHKOV, I. V.; BUTIN*, A. V.; Tetrahedron 68 (2012) 22, 4252-4258, http://dx.