ALPHA-CARBOLINE DERIVATIVES AND METHODS FOR PREPARATION THEREOF
申请人:Mizuno Masahiro
公开号:US20090326229A1
公开(公告)日:2009-12-31
To provide methods for preparing alpha-carboline derivatives in few steps, as well as conveniently and industrially advantageously. A method for preparation of a compound represented by Formula (II) or a salt thereof, comprising subjecting a compound represented by Formula (I) or a salt thereof to a ring closure reaction in the presence of a palladium catalyst, a ligand, and a base; a method for preparation of a compound represented by Formula (IX) or a salt thereof, comprising subjecting a compound represented by Formula (VII) or a salt thereof to a ring closure reaction in the presence of a palladium catalyst, a ligand, and a base, and subsequently to an aromatization reaction; and methods for preparation of compounds represented by Formulae (XV), (XVII), and (XIX) or a salt thereof, comprising subjecting respective compounds represented by Formulae (II) and (IX) or a salt thereof to a reaction for introducing a leaving group when necessary, and subsequently to a coupling reaction: wherein the symbols respectively represent the same meaning as defined in the present specification.
An efficient sequence of Pd catalyzed amination and direct C-H arylation for a synthesis of pharmacologically important alpha-carbolines is described. The outstanding feature in the synthetic sequence is that a combination of DBU and 2-(dicyclohexylphosphino)biphenyl (DCHPB) plays a critical role to not only enhance the reactivity but also suppress hydrodehalogenation in the direct C-H arylation step. The reaction protocol provides alpha-carbolines with various substituents including base-sensitive ester and ketone moieties in moderate to excellent yields. Moreover, combination with Cu catalyzed amination further enhanced the versatility of the alpha-carboline synthesis. (C) 2014 Elsevier Ltd. All rights reserved.