title: Pd-catalyzed cascade cyclization by intramolecular Heck insertion of an allene-allylic amination sequence: application to the synthesis of 3,4-fused tricyclic indoles.
abstract: A novel Pd-catalyzed cascade cyclization by intramolecular Heck insertion of an allene-allylic amination sequence was developed. Allenes tethered to ortho-iodoaniline derivatives at the meta-position were reacted with 5-10 mol % of Pd catalyst and 4 equiv of K2CO3 in DMSO at 90 °C, producing 3,4-fused tricyclic 3-alkylidene indoline derivatives in moderate to excellent yield. The reaction products were divergently transformed into three types of 3,4-fused tricyclic indole derivatives, successfully demonstrating the versatile properties of the reaction products.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Nakano
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Inoue
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Hamada
authors.affiliation: Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Nemoto
mesh_terms: D000586:Amination; D002384:Catalysis; D003500:Cyclization; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D010165:Palladium