title: Catalytic Asymmetric Synthesis of 3-Indolyl Methanamines Using Unprotected Indoles and N-Boc Imines under Basic Conditions.
abstract: A chiral imidazolidine-containing NCN/Pd-OTf catalyst (C4) promoted the nucleophilic addition of unprotected indoles to N-Boc imines. Using sulfinyl amines as the N-Boc imine precursors, the combined use of C4 with K2CO3activated the NH indoles to give chiral 3-indolyl methanamines with up to 98 % ee. Compared with conventional acid-catalyzed Friedel-Crafts reactions, this reaction proceeds under mildly basic conditions and is advantageous for the use of acid-sensitive substrates.
authors.affiliation: Molecular Chirality Research Center, Synthetic Organic Chemistry, Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba, 263-8522, Japan.
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Arai
authors.affiliation: Molecular Chirality Research Center, Synthetic Organic Chemistry, Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi, Inage, Chiba, 263-8522, Japan.
authors.forename: Junki
authors.initials: J
authors.lastname: Kakino
keywords: asymmetric catalysis; imines; indole; ligands; palladium