http://aether.cmi.ua.ac.be/artikels/Artikels%20Gitte/Artikels/Reviews/Trans.%20Metal.%20catal.%20reactions%20Chem.%20rev.%20042127.pdf

Transition-Metal-Catalyzed Reactions in Heterocyclic Synthesis

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.

Synthesis and Applications

Use of Lawesson's reagent in organic syntheses.

Compounds useful for treating cellular proliferative diseases and disorders by modulating the activity of KSP are disclosed.

Compounds, compositions, and methods

Preparation de nouveaux composes diamide lipophile et essai comme ionophores pour Li avec des electrodes a membrane de PVC

Comparative study of neutral carriers in polymeric lithium ion selective electrodes

Efficient atom economic approaches towards macrocyclic crownamides via ring closure metathesis

Stereoselective synthesis of dihydrothiadiazinoazines and dihydrothiadiazinoazoles and their pyrolytic desulfurization ring contraction

The 6-β-arylvinyl-2- and 4-glucosyl-3-thioxo-2,3-dihydro-1,2,4-triazin-5(4H)-ones were synthesized with high selectivity using the recently developed amino protecting group strategy. The structure of these new glucosides was established chemically and spectroscopically. Also, some interesting chemical transformations and rearrangements were observed.

Selective Synthesis and Structure of 6-Arylvinyl-2- and 4-Glucosyl-1,2,4-triazines of Expected Interesting Biological Activity

Sixteen new 14-17-macrocyclic dibenzo and tribenzodioxadiamides and trioxadiamides (macrooxacyclams, e.g., 5,6,7,8,9,10,16,17-octahydrodibenzo[e,m][1,4,8,11]dioxadiazatetradecine-5,10-dione) 13-28 have been prepared. Moderate to good yields (40-90%) of 13-28 were achieved in the macrocyclization step by reacting the dipotassium salts of 1,2-bis(2-hydroxybenzoylamino)ethanes 6, 7 and 1,2-bis(2-hydroxybenzoylamino)benzenes 8, 9 with the appropriate dihaloalkane or ditosylate in dimethylformamide. Alkylation of 13 and 25 with an appropriate halo compound in tetrahydrofuran and sodium hydride yielded the corresponding N,N'-dialkylmacrooxacyclams 29-33. The stereochemical purity of the latter was proved by 1 H NMR and 13 C NMR

Yehia A. Ibrahim

Papers

Comparative study of neutral carriers in polymeric lithium ion selective electrodes

Efficient atom economic approaches towards macrocyclic crownamides via ring closure metathesis

Stereoselective synthesis of dihydrothiadiazinoazines and dihydrothiadiazinoazoles and their pyrolytic desulfurization ring contraction

Selective Synthesis and Structure of 6-Arylvinyl-2- and 4-Glucosyl-1,2,4-triazines of Expected Interesting Biological Activity

Efficient Synthesis of a Range of Benzo-Substituted Macrocyclic Diamides