in acetone byproducts: AgCl; Ar-atmosphere; stirring Rh-complex with AgOTf for 10 min, filtration offof AgCl (Celite), dropwise addn. to ligand (over 15 min), stirring for 1 h; concn. (reduced pressure), pptn. on addn. of Et2O and then hexane, collection (filtration, washing (hexane), drying (vac.); elem. anal.;