Insertion and Coordination Reactions of Titanium(IV) Metallocene Zwitterions

Reaction of the titanium borate zwitterion complex (η 5 -C 5 Me 4 SiMe 2 N t Bu)Ti(η 3 -CH 3 (CH) 3 CH 2 B(C 6 F 5 ) 3 ) ( 1 ) with carbon monoxide results in the formation of the novel titanium−acyl borate complex (η 5 -C 5 Me 4 SiMe 2 N t Bu)Ti(η 3 -CH 3 (CH) 3 CH 2 COB(C 6 F 5 ) 3 ) ( 2 ). Addition of 1 equiv of PMe 3 to 1 results in the loss of B(C 6 F 5 ) 3 to give (η 5 -C 5 Me 4 SiMe 2 N t Bu)Ti(1,3-pentadiene) and Me 3 P·B(C 6 F 5 ) 3 . Addition of (CH 3 ) 3 CN⋮C to 1 results in the formation of the isocyanide adduct (η 5 -C 5 Me 4 SiMe 2 N t Bu)Ti(CNC(CH 3 ) 3 )(η 3 -C 5 H 8 B(C 6 F 5 ) 3 ) ( 3 ). The X-ray crystal structures of 2 and 3 were determined.