Aryl Ferrophites – A New Class of Ligands for Asymmetric Catalysis

Enantiopure lithiated 1,2‐ferrocenes, [CpFe{1,2‐η5‐C5H3(Ar)(Li)}] (Ar = Ph, 4‐CF3C6H4, 1‐C10H7), react readily with PhOP(OR)2 to yield [CpFe{1,2‐η5‐C5H3(Ar)P(OR)2}] (R = Ph, 1,1′‐biphenyl‐based, 1,1′‐binaphthyl‐based) efficiently. Traditional routes to these species, involving the use of chlorophosphites ClP(OR)2 were found to be ineffective. These “ferrophite” ligands have been characterised by X‐ray crystallography (4 examples) and shown to be effective in both nickel‐catalysed addition of AlMe3 to PhCHO (up to 77 % ee) and copper(I)‐catalysed additions of organoaluminium reagents to enones (up to 92 % ee). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)