Conversion of perfluorobenzyl complexes of rhodium to fluorinated oxarhodacycles

The perfluorobenzylrhodium complex: [Cp*Rh(CO)(CF2C6F5)(I) 1 (Cp* = C5Me5) reacts with N-methylmorpholine-N-oxide (NMO) with loss of CO2 and formation of the iodo-bridged dimer [Cp*Rh(mu (2)-I)(CF2C6F5)](2), 5, which has been characterized by,X-ray crystallography. While attempts to prepare hydroxo complexes by reaction of [Cp*Rh(PMe3)(CF2C5)(I)], 3, with sources of hydroxide were unsuccessful, treatment of 3 with moist silver oxide affords the:mametallacycle [Cp*(PMe3)RhO(C6F4)CF2], 9, which undergoes rapid hydrolysis-of the alpha -CF2 group by adventitious moisture to afford the crystallographically characterized analogue [Cp*(PMe3)RhO(C6F4)C=O], 10. A brief discussion of possible mechanisms is presented.