Pd-Catalyzed Tandem sp²–sp³ Coupling Reactions of Chiral Stannolanes: An Efficient Preparation of Optically Active Tetrahydrobenz[<i>f</i>]isoindoles

A novel double Migita–Kosugi–Stille coupling reaction with dihydrostannolanes, which are readily available from a radical cascade reaction, was achieved with dihalobenzenes in the presence of a palladium catalyst. Use of unsymmetrical 1-bromo-2-iodobenzene derivatives accomplished the double coupling reaction which gave tetrahydrobenz[<i>f</i>]isoindoles in a regioselective manner

Pd-Catalyzed Tandem sp²–sp³ Coupling Reactions of Chiral Stannolanes: An Efficient Preparation of Optically Active Tetrahydrobenz[<i>f</i>]isoindoles

A novel double Migita–Kosugi–Stille coupling reaction with dihydrostannolanes, which are readily available from a radical cascade reaction, was achieved with dihalobenzenes in the presence of a palladium catalyst. Use of unsymmetrical 1-bromo-2-iodobenzene derivatives accomplished the double coupling reaction which gave tetrahydrobenz[<i>f</i>]isoindoles in a regioselective manner

Pd-Catalyzed Tandem sp²–sp³ Coupling Reactions of Chiral Stannolanes: An Efficient Preparation of Optically Active Tetrahydrobenz[<i>f</i>]isoindoles

A novel double Migita–Kosugi–Stille coupling reaction with dihydrostannolanes, which are readily available from a radical cascade reaction, was achieved with dihalobenzenes in the presence of a palladium catalyst. Use of unsymmetrical 1-bromo-2-iodobenzene derivatives accomplished the double coupling reaction which gave tetrahydrobenz[<i>f</i>]isoindoles in a regioselective manner

Concise Synthesis of 2-Benzazepine Derivatives and Their Biological Activity

2-Benzazepines, which are potentially good candidates for new drug therapies to treat skin wounds, were readily prepared from substituted cinnamylamide via an intramolecular Friedel–Crafts reaction. With few steps and effective reactions, the procedure enables a rapid derivatization of 2-benzazepines. Moreover, optically active 4-substituted-2-benzazepines were prepared from chiral α-substituted cinnamylamides, which were readily prepared by asymmetric α-alkylation of chiral cinnamyl oxazolidinone amides. We have easily prepared a library of more than 20 derivatives and examined the biological activity of the compounds

Kinetic Study of the 7-<i>endo</i> Selective Radical Cyclization of <i>N</i>-<i>tert</i>-Butyl‑<i>o</i>‑bromobenzylmethacryl Amides: Kinetic Investigation of the Cyclization and 1,7-Hydrogen Transfer of Aromatic Radicals

A kinetic investigation of the radical cyclization of <i>N</i>-<i>tert</i>-butyl-<i>o</i>-bromobenzyl­methacryl amides to give 2-benzazepines via 7-<i>endo</i> selective cyclization was undertaken. The aryl radical generated from the amide precursor by treatment with Bu₃SnH gave the three compounds, which are a 7-<i>endo</i> cyclized adduct, a 6-exocyclized adduct, and a reduced product. The cyclization reactions under various Bu₃SnH concentrations were traced by GC analysis. The 7-<i>endo</i>/6-<i>exo</i> selectivity was constant irrespective of variation in Bu₃SnH concentration. These results revealed that regioselectivity is controlled in a kinetic manner and that there is no possibility of a neophyl rearrangement. The use of Bu₃SnD revealed that 1,7-hydrogen transfer, in which an aryl radical abstracts a hydrogen atom from the methallylic methyl group, occurs during the reaction. Hydrogen abstraction from toluene, the reaction solvent, was also observed. The 1,7-transfer rate depended on the Bu₃SnX (X = H or D), and the reaction kinetics was examined. The <i>k</i>_H/<i>k</i>_D value for the hydrogen abstraction of aryl radical from Bu₃SnX (X = H or D) was estimated using 4-bromoanisol. The utilization of these values revealed the overall reaction kinetics and relative rates for the cyclization and reduction by Bu₃SnX (X = H or D). Kinetic parameters for hydrogen abstraction from toluene by aryl radicals were also estimated