title: Asymmetric synthesis of N-allylic indoles via regio- and enantioselective allylation of aryl hydrazines.
abstract: The asymmetric synthesis of N-allylic indoles is important for natural product synthesis and pharmaceutical research. The regio- and enantioselective N-allylation of indoles is a true challenge due to the favourable C3-allylation. We develop here a new strategy to the asymmetric synthesis of N-allylic indoles via rhodium-catalysed N-selective coupling of aryl hydrazines with allenes followed by Fischer indolization. The exclusive N-selectivities and good to excellent enantioselectivities are achieved applying a rhodium(I)/DTBM-Segphos or rhodium(I)/DTBM-Binap catalyst. This method permits the practical synthesis of valuable chiral N-allylated indoles, and avoids the N- or C-selectivity issue.
authors.affiliation: Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg im Breisgau 79104, Germany.
authors.forename: Kun
authors.identifier: 0000000245167563
authors.initials: K
authors.lastname: Xu
authors.affiliation: Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg im Breisgau 79104, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gilles
authors.affiliation: Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, Freiburg im Breisgau 79104, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Breit
mesh_terms: D000466:Alkadienes / Q000737:chemistry*; D000498:Allyl Compounds / Q000138:chemical synthesis*; D048588:Benzoxazines / Q000138:chemical synthesis; D002384:Catalysis; D006834:Hydrazines / Q000737:chemistry*; D007211:Indoles / Q000138:chemical synthesis*; D009025:Morpholines / Q000138:chemical synthesis; D009281:Naphthalenes / Q000138:chemical synthesis; D010936:Plant Extracts / Q000138:chemical synthesis; D012238:Rhodium / Q000737:chemistry; D013237:Stereoisomerism; D014749:Vincamine / Q000138:chemical synthesis
chemical_list: D000466:Alkadienes; D000498:Allyl Compounds; D048588:Benzoxazines; D006834:Hydrazines; D007211:Indoles; D009025:Morpholines; D009281:Naphthalenes; D010936:Plant Extracts; C507332:Yuremamine; C025947:propadiene; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D014749:Vincamine; D012238:Rhodium