Reactivity of 3-Imino-Functionalized Indoles with Rare-Earth-Metal Amides: Unexpected Substituent Effects on C–H Activation Pathways and Assembly of Rare-Earth-Metal Complexes
作者:Xiancui Zhu、Yang Li、Yun Wei、Shaowu Wang、Shuangliu Zhou、Lijun Zhang
DOI:10.1021/acs.organomet.6b00221
日期:2016.6.13
The reactivities of different 3-imino-fiinctionalized indoles with rare -earth -metal amides [(Me3Si)(2)N](3)RE(mu-Cl)Li(THF)(3) were studied to reveal unexpected substituent effects on C H bond activation pathways, leading to the formation of unusual rare -earth -metal complexes. The reactions of 3-(tert-butylimino)indole with [(Me3Si)(2)N](3)RE(mu-ClLi(THF)(3) produced tetranuclear rare -earth -metal complexes eta(1):mu(2)eta(1):eta(1)):eta(1)-3-(tBuN=CH)C8H4N]RE,(mu(2)-Cl-2)HF)[N(SiMe3)(2)](eta(1):eta 1(7)[mu(3)(tBuN=-CH)C8H5NbLi)}(2) (RE = Ho (la), Er (lb)), incorporating a unique indoly1-1,2-dianion through sp2 C H activation bonded with the central metal in eta(1) :(mu(2)-eta(1) :eta(1)) ions of 3,(phenylimino)indole with [(Me3Si)(2)N](3)RE(mu-Cl)Li(THF)(3) afforded novel binuclear complexes formulated as 3-[PhNCH(CH2SiMe2)N(SiMe3)]C8H5NRE(THF)(t(2)-COLi(THF)(2)](2) (RE = Y (2a), Sm (2b), Dy (2c), Yb (2d)) through an unexpected sp3 C H bond activation with subsequent C C bond coupling reactions. Treatment of 3-(2-methylphenylimino)indole or 3-(4methylphenylimino)indole with [(Me3Si)(2)N](3)Yb(y-Cl)Li(THF)(3) generated the corresponding dinuclear rare -earth -metal amido complexes (3-[(2-MePh)NCH(CH2SiMe2)N(SiMe3)]C8H5NYb(THF)(y(2)-COLi(THF)(2)}(2) (3) and 3-[(4-MePh)NCH(CH2SiMe2)N(SiMe3)]C8H5NYb(THF)(eta(2)-COLi(THF)(2)](2) (4), following the same pathway for the formation of complexes 2a d. Treatment of 3-(4-tert-butylphenylimino)indole with [(Me3SO2N](3)RE(eta-COLi(THF)(3) afforded new hexanuclear rareearth -metal complexes 3-[(4-tBu-Ph)NHCH(CH2SiMe2)N(SiMe3)]C8H5NREN(SiIVIe(3))(2)}(6) (RE = Dy (5a), Ho (5b), Er (5c)) via sp3 C-H bond activation followed by C-C bond coupling reactions. In contrast, under the same conditions as those for the preparation of 5, the reaction with the corresponding yttrium complex provided the new heterohexayttrium complex 3-[(4-tBuPh)NCH(CH2SiMe2)N(SiMe3)]C8H5NYN(SiMe3)21i(THF)}(6) (6), having a 4-tBu-anilido moiety. All of these complexes were fully characterized by elemental analysis, spectroscopic methods, and X-ray structure analysis. Plausible pathways for the formation of these different rare -earth -metal complexes were proposed.