The challenge of cyclic and acyclic schiff bases and related derivatives

International Tables for X-Ray Crystallography (Published for the International Union of Crystallography.) Vol. 1: Symmetry Groups. Edited by Norman F. M. Henry and Kathleen Lonsdale. Pp. xi + 558. (Birmingham: Kynoch Press, 1952.) 105s.

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International Tables for X-Ray Crystallography

This review is focused on the use of solid Lewis acids to promote catalytic oxidations. While the concept of using Lewis acids to promote the reaction of organic substrates with oxidizing reagents is widely accepted in homogeneous catalysis, this concept has not become evident and generally used in heterogeneous catalysis until recent days. Certainly the development of new Lewis acid solids active and selective for catalytic oxidations is an urgent need and a challenging scientific target for some substrates especially using environmentally friendly oxidants. Since the replacement of current stoichiometric oxidations for the production of fine chemicals by environmentally benign catalytic oxidations is one of the major tasks in green chemistry, solid Lewis acids are called to play a crucial role to accomplish this goal. In the review, we will see the still important role that stoichiometric oxidations play in our daily life, and how they are being substituted by catalytic oxidations. At this point, three general mechanisms in which Lewis acids are involved will be described, and the material has been organized starting from homogeneous and ending with solid catalysts for heterogeneous oxidations. A bridge between the two will be established by presenting catalytic systems that can fill the gap between the two systems helping to rationalize the nature of the catalytic active sites in solid systems. This review is obviously focused on solid oxidation catalysts, and the core of the review is organized to show the evolution from the simplest strategy for heterogeneizing homogeneous catalysts, i.e., supporting the active species on large surface area solids, to the more elaborate ones in which the active sites are part of the solid structure. Given the importance of metallosilicates, and more specifically titanosilicates, as catalysts in commercial processes, special attention has been paid to these types of materials. Although sufficient references are provided to early seminal work, special emphasis has been given to most recent contributions to this area, particularly of the last 10 years. Patent literature has also been extensively covered in this review. Examples to illustrate the concepts have been selected among recent publications, and an effort has been made to present a series of commercial and near commercial processes based on catalytic oxidations. Finally, two * E-mail: acorma@itq.upv.es. 3837 Chem. Rev. 2002, 102, 3837−3892

Lewis acids as catalysts in oxidation reactions: from homogeneous to heterogeneous systems.

N-silylated benzamidines: versatile building blocks in main group and coordination chemistry

https://escholarship.org/content/qt1kp1t47g/qt1kp1t47g.pdf?t=o0hb1w

Radical ligand-containing single-molecule magnets

Coordination of 2,2'-bipyridyl and 1,10-phenanthroline to substituted ytterbocenes: An experimental investigation of spin coupling in lanthanide complexes

https://escholarship.org/content/qt39r5f5bw/qt39r5f5bw.pdf?t=p0t201

Electron-transfer reactions of divalent ytterbium metallocenes. Synthesis of the series [(Me5C5)2Yb]2[.mu.-E] (E = oxygen, sulfur, selenium, or tellurium) and crystal structure of [(Me5C5)2Yb]2[.mu.-Se]

Preparation of Coordination Compounds of Cp*2Yb with Heterocyclic Nitrogen Bases: Examples of Antiferromagnetic Exchange Coupling across Bridging Ligands

Heptadentate ligands for the lanthanides. The first structurally characterized example of a lanthanide heptadentate ligand complex: [tris(3-aza-4-methyl-6-oxohept-4-en-1-yl)amine]ytterbium(III)

https://escholarship.org/content/qt6rh182wc/qt6rh182wc.pdf?t=p0uvm8

Electron-transfer chemistry of (Me5C5)2Yb: cleavage of diorganoperoxide and related chalcogenides to give (Me5C5)2Yb(ER)(L) (E = O, S, Se, or Te; L = a Lewis base). Crystal structure of (Me5C5)2Yb(TePh)(NH3)

David J. Berg

Papers

Coordination of 2,2'-bipyridyl and 1,10-phenanthroline to substituted ytterbocenes: An experimental investigation of spin coupling in lanthanide complexes

Electron-transfer reactions of divalent ytterbium metallocenes. Synthesis of the series [(Me5C5)2Yb]2[.mu.-E] (E = oxygen, sulfur, selenium, or tellurium) and crystal structure of [(Me5C5)2Yb]2[.mu.-Se]

Preparation of Coordination Compounds of Cp*2Yb with Heterocyclic Nitrogen Bases: Examples of Antiferromagnetic Exchange Coupling across Bridging Ligands

Heptadentate ligands for the lanthanides. The first structurally characterized example of a lanthanide heptadentate ligand complex: [tris(3-aza-4-methyl-6-oxohept-4-en-1-yl)amine]ytterbium(III)

Electron-transfer chemistry of (Me5C5)2Yb: cleavage of diorganoperoxide and related chalcogenides to give (Me5C5)2Yb(ER)(L) (E = O, S, Se, or Te; L = a Lewis base). Crystal structure of (Me5C5)2Yb(TePh)(NH3)