Rare-earth metal complexes stabilized by amino-phosphine ligand. Reaction with mesityl azide and catalysis of the cycloaddition of organic azides and aromatic alkynes
作者:Liu, B;Cui, DM
关键字:terminal alkynes,structural-characterization,intramolecular hydroamination/cyclization,isoprene polymerization,metallocene complexes,anilido-phosphinimine,organolanthanide,dimerization,chemistry,acetylcholinesterase
论文来源:期刊
具体来源:http://pubs.rsc.org/en/Content/ArticleLanding/2009/DT/B811363G#!divAbstract
发表时间:2009年
Stoichiometric reactions between mesityl azide (MesN3, Mes = 2,4,6-C6H2Me3) and amino-phosphine ligated rare-earth metal alkyl, LLn(CH2SiMe3)2(THF) (L = (2,6-C6H3Me2)NCH2C6H4P(C6H5)2; Ln = Lu (1a), Sc (1b)), amide, LLu(NH(2,6-C6H3iPr2))2(THF) (2) and acetylide at room temperature gave the amino-phosphazide ligated rare-earth metal bis(triazenyl) complexes, [L(MesN3)]Ln[(MesN3)(CH2SiMe3)]2 (Ln = Lu (3a); Sc (3b)), bis(amido) complex [L(MesN3)]Lu[NH(2,6-C6H3iPr2)]2 (4), and bis(alkynyl) complex (5) (L(MesN3)Lu (CCPh)2)2, respectively. The triazenyl group in 3 coordinates to the metal ion in a rare η2-mode viaNβ and Nγ atoms, generating a triangular metallocycle. The amino-phosphazide ligand, L(MesN3), in 3, 4 and 5 chelates to the metal ion in a η3-mode viaNα and Nγ atoms. In the presence of excess phenylacetylene, complex 3a isomerized to 3′, where the triazenyl group coordinates to the metal ion in a η3 mode viaNα and Nγ atoms. Complexes 1, 2, 3 and 4 have shown an unprecedented catalytic activity towards the cycloaddition of organic azides and aromatic alkynes to afford 1,5-disubstituted 1,2,3-triazoles selectively.