Substitution-Controlled Selective Formation of Hexahydrobenz[e]isoindoles and 3-Benzazepines via In(OTf)₃-Catalyzed Tandem Annulations

Abstract

A dramatic N-substituent controlled tandem annulation of 2-(2-(2-bromoethyl)phenyl)-1-sulfonylaziridines with 1,3-dicarbonyl compounds has been developed. When the N-substituent was a 4-methylbenzenesulfonyl group (Ts), sequential ring opening of aziridines, nucleophilic substitution, and lactamization took place to provide a series of hexahydrobenz[ e]isoindole compounds in good yields with good diastereoselectivities. By contrast, 3-benzazepine compounds were afforded in good yields via ring opening of aziridines and nucleophilic substitution when the N-substituent was the 4-nitrobenzenesulfonyl group (Ns).

Highly Selective Synthesis of Tetrahydronaphthaleno[60]fullerenes via Fullerene-Cation-Mediated Intramolecular Cyclization

“…The residue was purified by flash chromatography on silica gel (petroleum ether/ethyl acetate, 10:1) to afford product 5b (4.26 g, 19.6 mmol, 98%). 20 1 H NMR (400 MHz, CDCl 3 ): δ 7.26 (dd, J 1 = 8.4 Hz, J 2 = 2.8 Hz, 1H), 7.22−7.18 (m, 1H), 6.94 (ddd, J 1 = 10.8 Hz, J 2 = 8.4 Hz, J 3 = 2.4 Hz, 1H), 3.77 (t, J = 6.8 Hz, 2H), 3.39 (br, 1H), 2.93 (t, J = 6.8 Hz, 2H). Literature data: 1 H NMR (400 MHz, CDCl 3 ) δ 7.28 (dd, J 1 = 8.0 Hz, J 2 = 1.5 Hz, 1H), 7.23−7.20 (m, 1H), 7.00 (ddd, J 1 = 8.0 Hz, J 2 = 7.5 Hz, J 3 = 1.5 Hz, 1H), 3.73 (t, J = 7.1 Hz, 2H), 3.34 (s, 1H), 2.89 (t, J = 7.1 Hz, 2H).…”

“…The organic layer was further dried over Na 2 SO 4 and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel (petroleum ether/ethyl acetate, 10:1) to afford product 5b (4.26 g, 19.6 mmol, 98%) …”

A NaHCO3 Promoted Three‐component Cyclization: Easy Access to Benzodisulfide Heterocycles

“…[27] In a word, benzodisulfide heterocycles are of great interest from a chemical and biological points of view, but their 3-arylimino derivatives have been much less studied. [26] In comparison, due to their cheapness and availability, 2halophenylacetic acids and its derivatives are often used as synthons in organic synthesis, [28,29] including the synthesis of cyclic compounds. [30,31] However, there is no reports on the synthesis of sulfur-containing heterocycles.…”

“…In comparison, due to their cheapness and availability, 2‐halophenylacetic acids and its derivatives are often used as synthons in organic synthesis, [28,29] including the synthesis of cyclic compounds [30,31] . However, there is no reports on the synthesis of sulfur‐containing heterocycles.…”

Synthesis of Chiral Tetrahydro-3-benzazepine Motifs by Iridium-Catalyzed Asymmetric Hydrogenation of Cyclic Ene-carbamates

“…Numerous racemic syntheses of 1-substituted tetrahydro-3-benzazepines have been developed, enabled mostly by intramolecular Friedel–Crafts-type alkylation, 5 ring enlargement, 6 reductive cyclization, 7 or arylation. 8 Despite their importance, fewer enantioselective methods have been developed to access enantioenriched products.…”