title: Enantioselective Access to Spirocyclic Sultams by Chiral Cp(x) -Rhodium(III)-Catalyzed Annulations.
abstract: Chiral spirocyclic sultams are a valuable compound class in organic and medicinal chemistry. A rapid entry to this structural motif involves a [3+2] annulation of an N-sulfonyl ketimine and an alkyne. Although the directing-group properties of the imino group for C-H activation have been exploited, the developments of related asymmetric variants have remained very challenging. The use of rhodium(III) complexes equipped with a suitable atropchiral cyclopentadienyl ligand, in conjunction with a carboxylic acid additive, enables an enantioselective and high yielding access to such spirocyclic sultams.
authors.affiliation: Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015, Lausanne, Switzerland.
authors.forename: Manh V
authors.initials: MV
authors.lastname: Pham
authors.affiliation: Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015, Lausanne, Switzerland. nicolai.cramer@epfl.ch.
authors.forename: Nicolai
authors.initials: N
authors.lastname: Cramer
mesh_terms: D002264:Carboxylic Acids / Q000737:chemistry; D002384:Catalysis; D006860:Hydrogen Bonding; D008024:Ligands; D015394:Molecular Structure; D009282:Naphthalenesulfonates / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013141:Spiro Compounds / Q000737:chemistry*
chemical_list: D002264:Carboxylic Acids; D008024:Ligands; D009282:Naphthalenesulfonates; D013141:Spiro Compounds; C016768:naphthosultone; D012238:Rhodium
keywords: C−H activation; asymmetric catalysis; chiral Cp ligands; rhodium; sultams