Rapid access to dimethylcyclopentadienyltitanium(IV)amidinate, (C5R5)TiMe2[(NRC)-C-1(R-2)NR3] (R = H and Me, R-2 = Me), libraries

Facile insertion of carbodiimides, (RN)-N-1=C=NR3, into a Ti-C-Me bond of ( C5R5)TiMe3 (R = H and Me) (2a and 2b, respectively) in pentane solutions at 25 degrees C provides a wide range of derivatives of (C5R5)TiMe2[(NRC)-C-1 (Me)NR3] (1) in high yield. Low barriers to racemization (less than or equa l to 15 kcal mol(-1)) have been determined for derivatives of 1 where R-1 n ot equal R-3, and further, a preliminary screen has found some of these to be Ziegler-Natta catalyst precursors for the polymerization of ethylene upo n activation with methylaluminoxane.