Exploiting Planar Chirality for the Generation of α-Ferrocenyl Stereogenic Centres
22 July 2005 (eFirst)
Addition of Grignard reagents R1MgBr (R1 = Me, Et, i-Pr, t-Bu, Ph) to 2-bromo- and 2-trimethylsilylferrocenecarboxaldehyde proceeded, in most cases, with high diastereoselectivity to generate α-ferrocenyl alcohols of S*,p S* configuration. Following conversion into their corresponding acetates, reaction with dimethylamine provided α-ferrocenyl amines with retention of configuration (R1 = Me, Et, Ph).
asymmetric synthesis - Grignard reactions - ligands - metallocenes - stereoselectivity