Yttrium and scandium complexes of a bulky bis(phosphinimine)carbazole ligand
摘要:
The synthesis and reactivity of a bulky bis(phosphinimine) carbazole pincer ligand (HL) bearing mesityl N-aryl groups is described. Reaction of HL with Y(CH2SiMe3)(3)(THF)(2) afforded a doubly cyclometalated organoyttrium complex, whereby the ligand was k(3)N, k(2)C coordinated to the metal via three nitrogen atoms and two ortho-metalated P-phenyl rings. Deprotonation of (HL) with (BuLi)-Bu-n liberated a monomeric and thermally stable lithium salt of the ligand (LLi). Salt metathesis reactions of LLi with ScCl3(THF)(3) and YCl3(THF)(3.5) generated the corresponding rare earth dichloro complexes, which were found to be monomeric and Lewis-base free. (C) 2014 Elsevier B. V. All rights reserved.
Yttrium and scandium complexes of a bulky bis(phosphinimine)carbazole ligand
摘要:
The synthesis and reactivity of a bulky bis(phosphinimine) carbazole pincer ligand (HL) bearing mesityl N-aryl groups is described. Reaction of HL with Y(CH2SiMe3)(3)(THF)(2) afforded a doubly cyclometalated organoyttrium complex, whereby the ligand was k(3)N, k(2)C coordinated to the metal via three nitrogen atoms and two ortho-metalated P-phenyl rings. Deprotonation of (HL) with (BuLi)-Bu-n liberated a monomeric and thermally stable lithium salt of the ligand (LLi). Salt metathesis reactions of LLi with ScCl3(THF)(3) and YCl3(THF)(3.5) generated the corresponding rare earth dichloro complexes, which were found to be monomeric and Lewis-base free. (C) 2014 Elsevier B. V. All rights reserved.
Organolutetium-Mediated Dearomatization and Functionalization of Pyrimidine Rings
作者:Kevin R. D. Johnson、Paul G. Hayes
DOI:10.1021/om400413e
日期:2013.8.12
The synthesis of a pentadentate NNNNN bis(phosphinimine)carbazole pincer ligand bearing two pyrimidine N-aryl rings is reported. A dialkyl lutetium complex of the ligand, prepared by alkane elimination with Lu-(CH2SiMe3)(3)(THF)(2), was found to undergo an unusual transformation involving a double alkyl shift whereby the -CH2SiMe3 groups on the metal migrated to both pyrimidine rings. This migration afforded a final product that featured alkyl-functionalized, dearomatized ligand pyrimidine rings.