Enantioselective Synthesis of 1‐Aryl Benzo[5]helicenes Using BINOL‐Derived Cationic Phosphonites as Ancillary Ligands. (21st October 2020)

• Record Type: Journal Article
• Authors: Redero, Pablo; Hartung, Thierry; Zhang, Jianwei; Nicholls, Leo D. M.; Zichen, Guo; Simon, Martin; Golz, Christopher; Alcarazo, Manuel
• Is Part Of: Angewandte Chemie. Volume 132:Number 52(2020)
• Page Start: 23733
• Page End: 23737
• Publication Date: 2020-10-21
• Subjects: [5]helicenes -- asymmetric catalysis -- cationic phosphonites -- gold catalysis -- ligand design; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202010021
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: The synthesis of unprecedented BINOL‐derived cationic phosphonites is described. Through the use of these phosphanes as ancillary ligands in Au I catalysis, a highly regio‐ and enantioselective assembly of appropriately designed alkynes into 1‐(aryl)benzo[5]carbohelicenes is achieved. The modular synthesis of these ligands and the enhanced reactivity that they impart to Au I ‐centers after coordination have been found to be the key features that allow an optimization of the reaction conditions until the desired benzo[5]helicenes are obtained with high yield and enantioselectivity. Abstract : A new family of α‐cationic phosphonites derived from BINOL has been synthesized. Their use as ancillary ligands in Au I catalysis allows the enantioselective assembly of 1‐aryl [5]helicenes with excellent yields and in up to 98 % ee .