title: Synthesis of diversely functionalized hexahydropyrrolo[2,3-b]indoles using domino reactions, olefination, isomerization and Claisen rearrangement followed by reductive cyclization.
abstract: Hexahydropyrrolo[2,3-b]indoles 6 were synthesized in five steps from indolin-3-one 8 by a general and efficient method, in which elements of molecular diversity were readily added onto the 3a-position of the pyrrolo[2,3-b]indole ring system. Horner-Wadsworth-Emmons reaction of 2-allyloxyindolin-3-ones 7, derived from indolin-3-one 8 and a variety of allylic alcohols, smoothly proceeded with successive Claisen rearrangement to give the corresponding 3-allyl-3-cyanomethylindolin-2-ones 15. Indolin-2-ones 15 were converted into pyrrolo[2,3-b]indoles 6 using partial hydrolysis followed by reductive cyclization with LiAlH(4). Synthesis of N-methylated pyrrolo[2,3-b]indole derivatives 23 and 26 is also described.
authors.affiliation: Meiji Pharmaceutical University, 2-522-1 Noshio, Kiyose, Tokyo 204-8588, Japan. kawasaki@my-pharm.ac.jp
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kawasaki
authors.forename: Atsuyo
authors.initials: A
authors.lastname: Ogawa
authors.forename: Romi
authors.initials: R
authors.lastname: Terashima
authors.forename: Toshiko
authors.initials: T
authors.lastname: Saheki
authors.forename: Naoko
authors.initials: N
authors.lastname: Ban
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: Ken-ei
authors.initials: KE
authors.lastname: Sakaguchi
authors.forename: Masanori
authors.initials: M
authors.lastname: Sakamoto
mesh_terms: D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D007202:Indicators and Reagents; D026121:Indole Alkaloids / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis*; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis*
chemical_list: D007202:Indicators and Reagents; D026121:Indole Alkaloids; D007211:Indoles; D011758:Pyrroles