Generating a New Chiral Ligand System for High-Valent Early Transition Metals — Synthesis and Structural Characterization ofC3-Symmetrical Tripodal Alkyl/Silyl Amido Complexes

Abstract

Keywords: Lithium / Amides / Chirality / Tripodal ligands / ZirconiumThe novel C 3 -chiral tripodal amine HC{SiMe 2 NH[(S)-3,3-dimethyl-2-butyl]} 3 (1) and its trilithium triamido derivative [HC{SiMe 2 N(Li)[(S)-3,3-dimethyl-2-butyl]} 3 ] (2) have been synthesized and characterized by X-ray diffraction. The lithium reagent was used for the synthesis of a C 3 -chiral amidozirconium complex [HC{SiMe 2 N[(S)-3,3-dimethyl-2-butyl]} 3 ZrCl] (3); the preparation of the analogous titanium compound was precluded by the redox activity of the metal.

[n.1.1]-(2,6)-Pyridinophanes: A New Ligand Type Imposing Unusual Metal Coordination Geometries

“…15,16 Similarly, fivecoordinated Rh(I) complexes [Rh(L){bis[(3,5-dimethyl-1pyrazolyl)methyl]ethylamine}]BF 4 (L ) cod, (CO) 2 ) have been found in the solid state (but not in solution) with one Rh-N distance longer by 0.47 Å. 16 The pyridinophanes may join the current range of facial preference ligands C 5 R 5 , RE(pyrazolyl) 3 (E ) N, C, B), 17,18 3-fold symmetric cyclic triamines 19 and thioethers, 20 and the various tripodal thianes, 21 phosphines, 22 tripyridine methanes, 23 and amides 24,25 in manipulating metal center thermodynamics and reactivity. The present work shows the ability of [2.1.1]-pyridinophanes to adapt to an η 2 -mode of binding, a capability of increasing importance in tris-pyrazolylborate chemistry.…”

“…The pyridinophanes may join the current range of facial preference ligands C 5 R 5 , RE(pyrazolyl) 3 (E = N, C, B), , 3-fold symmetric cyclic triamines and thioethers, and the various tripodal thianes, phosphines, tripyridine methanes, and amides , in manipulating metal center thermodynamics and reactivity. The present work shows the ability of [2.1.1]-pyridinophanes to adapt to an η 2 -mode of binding, a capability of increasing importance in tris-pyrazolylborate chemistry.…”

Synthesis and Molecular Structure of aC3-chiral Triaminodistannane

“…Its [2,2,2]bicyclooctane-related cage structure, comprising the trisilylsilane unit and the triamido-tin fragment, as well as the Sn±Sn bond (2.7978(15)±2.8020(15) A Ê in the three crystallographically independent molecules) were established by a single crystal X-ray structure analysis: Space proup P3, Z = 3, lattice dimensions at 293(2) K: a = 17.724(3), c = 10.597(2) A Ê , R = 0.0374.The facile accessibility of enantiomerically pure C 3 -chiral tridentate amido ligands [1] has opened up the systematic investigation of their main group and transition metal complexes [2,3]. We previously reported the synthesis and structural characterization of the chiral lithium triamidostannate(II) [HC{SiMe 2 N[(S)±CH(Me)Ph]} 3 SnLi(thf)] (1), the first chiral tin(II) compound [4].…”

“…The facile accessibility of enantiomerically pure C 3 -chiral tridentate amido ligands [1] has opened up the systematic investigation of their main group and transition metal complexes [2,3]. We previously reported the synthesis and structural characterization of the chiral lithium triamidostannate(II) [HC{SiMe 2 N[(S)±CH(Me)Ph]} 3 SnLi(thf)] (1), the first chiral tin(II) compound [4].…”