Modification of Yttrium Silyl-Bridged Amide Alkyl Complexes through Si-H/C-H Cross-Dehydrocoupling of Silanes with Silylamino Ligand: Synthesis, Reactivity, and Mechanism.

A new method for modification of silyamino ligand has been developed through mono/dual C(sp3 )-H/Si-H cross-dehydrocoupling of it with silanes. The reaction of LY[ eta 2 -(C,N)-CH 2 Si(Me 2 )NSiMe 3 ] (L = L' (Bis-2,6-diisopropylphenyl- b -diketiminato) ( 1 L' ); L = Tp Me2 ( 1 TpMe2 )) with two equiv of PhSiH 3 in toluene gave Complexes LY[ eta 2 -(C,N)-C(SiH 2 Ph) 2 Si(Me 2 )NSiMe 3 ] (L = L' ( 2 L' ); L = Tp Me2 ( 2 TpMe2 )). Moreover, 1 TpMe2 reacted with secondary silanes Ph 2 SiH 2 and Et 2 SiH 2 to afford the corresponding mono C-H activation products Tp Me2 Y[ eta 2 -(C,N)-CH(SiHR 2 )Si(Me 2 )NSiMe 3 ] (R = Ph ( 4b ); R = Et ( 4c )). Study on their reactivity showed that Tp Me2 Y[ eta 2 -(C,N)-CH(SiH 2 Ph)Si(Me 2 )NSiMe 3 ](THF) ( 4a ) facilely react with two equiv of benzothiazole to give an unusual 1,1-addition of the C=N bond of benzothiazolyl unit with Si-H bond and C-H/Si-H cross-dehydrocoupling product (Tp Me2 )Y[ eta 3 -(N,N,N)-N(SiMe 3 )SiMe 2 CH 2 Si(Ph)(CSC 6 H 4 N)(CHSC 6 H 4 N)] ( 5 ). These results indicated that this modification endowed the silylamino ligand with more novel reactivities.