Synthesis of iridium complexes with novel planar chiral chelating imidazolylidene ligands

✍ Scribed by Carsten Bolm; Thilo Focken; Gerhard Raabe

• Book ID: 104359880
• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 322 KB
• Volume: 14
• Category: Article
• ISSN: 0957-4166
• DOI: 10.1016/s0957-4166(03)00353-7

✦ Synopsis

New planar chiral imidazolium salts such as (S p )-1- [4-(4,4-dimethyl-4,5-dihydrooxazolyl)[2.2]paracyclophane-12ylmethyl]-3-methyl imidazolium bromide (S p )-8a have been synthesized starting from enantiopure 4,12dibromo[2.2]paracyclophane (S p )-4. Deprotonation of these salts followed by reaction with [Ir(COD)Cl] 2 yielded chelating iridium imidazolylidene complexes 9a-c, which were applied in asymmetric hydrogenations of alkenes. The solid state structure of (S p )-9c was determined by single-crystal X-ray structure analysis.