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Modification of Yttrium Silyl‐Bridged Amide Alkyl Complexes through Si−H/C−H Cross‐Dehydrocoupling of Silanes with a Silylamino Ligand: Synthesis, Reactivity, and Mechanism
Author(s) -
You Qing,
Zhang Jie,
Zhou Xigeng
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202001207
Subject(s) - chemistry , silanes , reactivity (psychology) , ligand (biochemistry) , alkyl , amide , medicinal chemistry , trifluoromethanesulfonate , silylation , stereochemistry , catalysis , organic chemistry , silane , medicine , biochemistry , alternative medicine , receptor , pathology
A new method for the modification of a silylamino ligand has been developed through mono and dual C(sp 3 )−H/Si−H cross‐dehydrocoupling with silanes. The reaction of [LY{η 2 ‐( C , N )‐CH 2 Si(Me 2 )NSiMe 3 }] (L=bis(2,6‐diisopropylphenyl)‐β‐diketiminato, L′ ( 1 L ′); L=tris(3,5‐dimethylpyrazolyl)borate, Tp Me2 ( 1 TpMe2 )) with 2 equivalents of PhSiH 3 in toluene gave the complexes [LY{η 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 the secondary silanes Ph 2 SiH 2 and Et 2 SiH 2 to afford the corresponding mono C−H activation products [Tp Me2 Y{η 2 ‐( C , N )‐CH(SiHR 2 )Si(Me 2 )NSiMe 3 }] (R=Ph ( 4 b ); R=Et ( 4 c )). The equimolar reaction of 1 TpMe2 with PhSiH 3 also produced the mono C−H activation product 4 a ([Tp Me2 Y{η 2 ‐( C , N )‐CH(SiH 2 Ph)Si(Me 2 )NSiMe 3 }(thf)]). A study of their reactivity showed that 4 a facilely reacted with 2 equivalents of benzothiazole by an unusual 1,1‐addition of the C=N bond of the benzothiazolyl unit to the Si−H bond to give the C−H/Si−H cross‐dehydrocoupling product [(Tp Me2 )Y{η 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 indicate that this modification endows the silylamino ligand with novel reactivity.