Directed Assembly of Transition-Metal-Coordinated Molecular Loops and Squares from Salen-Type Components. Examples of Metalation-Controlled Structural Conversion
摘要:
A series of transition-metal-containing molecular "loops" and "squares" has been prepared via a directed-assembly approach and characterized. The molecular loops were prepared from the reaction of cis-(PEt3)(2)Pt(OTf)(2) with bis(4-pyridyl)-functionalized free-base salen-type ligands. Zn(II)-metalation of the salen-type ligands in the molecular loops converts the loops to molecular squares. Alternatively, the squares can be obtained by the directed assembly of cis-(PEt3)2Pt(OTf)2 and bis(4-pyridyl)-functionalized Zn(II)salen-type ligands. A concentration-dependent dynamic equilibrium between cyclic species was observed when bis(3-pyridyl)-functionalized free-base salen-type ligand was employed in the reaction. Zn(II) or Cr(III) metalation of the free-base ligand shifted the equilibrium to the single dimeric species. The incorporation of multiple reactive metal sites into a single, cavity-containing supramolecular structure points toward catalytic applications for these new assemblies.
A general route to pyridine-modified salicylaldehydes via Suzuki coupling
摘要:
An efficient method for the preparation of 5-(3-pyridyl)- and 5-(4-pyridyl)salicylaldehydes by the palladium-catalyzed cross-coupling reaction of either 4-pyridylboronic acid or diethyl-(3-pyridyl)borane and bromosalicylaldehydes is described. (C) 2001 Published by Elsevier Science Ltd.
Directed Assembly of Transition-Metal-Coordinated Molecular Loops and Squares from Salen-Type Components. Examples of Metalation-Controlled Structural Conversion
作者:Shih-Sheng Sun、Charlotte L. Stern、SonBinh T. Nguyen、Joseph T. Hupp
DOI:10.1021/ja037378s
日期:2004.5.1
A series of transition-metal-containing molecular "loops" and "squares" has been prepared via a directed-assembly approach and characterized. The molecular loops were prepared from the reaction of cis-(PEt3)(2)Pt(OTf)(2) with bis(4-pyridyl)-functionalized free-base salen-type ligands. Zn(II)-metalation of the salen-type ligands in the molecular loops converts the loops to molecular squares. Alternatively, the squares can be obtained by the directed assembly of cis-(PEt3)2Pt(OTf)2 and bis(4-pyridyl)-functionalized Zn(II)salen-type ligands. A concentration-dependent dynamic equilibrium between cyclic species was observed when bis(3-pyridyl)-functionalized free-base salen-type ligand was employed in the reaction. Zn(II) or Cr(III) metalation of the free-base ligand shifted the equilibrium to the single dimeric species. The incorporation of multiple reactive metal sites into a single, cavity-containing supramolecular structure points toward catalytic applications for these new assemblies.
A general route to pyridine-modified salicylaldehydes via Suzuki coupling
作者:Gregory A. Morris、SonBinh T. Nguyen
DOI:10.1016/s0040-4039(01)00106-x
日期:2001.3
An efficient method for the preparation of 5-(3-pyridyl)- and 5-(4-pyridyl)salicylaldehydes by the palladium-catalyzed cross-coupling reaction of either 4-pyridylboronic acid or diethyl-(3-pyridyl)borane and bromosalicylaldehydes is described. (C) 2001 Published by Elsevier Science Ltd.