2,4,6-Trichloro-1,3,5-triazine Catalyzed Chemoselective Transthioacetalization of Aldehyde Acetals and Oxathioacetals

A mild and efficient transthioacetalization of aldehyde acetals and oxathioacetals was carried out using 2,4,6-trichloro-1,3,5-triazine as a mild and inexpensive catalyst. Chemoselective transacetalization is impressive as aldehyde O,O- and O,S-acetals are converted into the corresponding S,S-acetals in the presence of ketones or their acetals and oxathiocetals in nearly quantitative yields.     

Morpholine Adsorbed on Silica Gel: A Novel and Mild Basic Catalyst for the Synthesis of α,β-Unsaturated Nitroalkenes

Summary.  Syntheses of α,β-unsaturated nitroalkenes have been carried out under mild condition using morpholine adsorbed on silica gel as a novel catalyst. Received February 14, 2000. Accepted March 28, 2000     

Chemoselective Silylation of Alcohols1

Hexamethyldisilazane (HMDS) in pesence of a catalytic amount of Envirocat EPZG^R silylates different alcohols in high yields with absolute chemoselectivity.

     

Envirocats,as Novel Solid‐Supported Catalysts for Friedel‐Crafts Acylation

The Friedel‐Crafts acylation reactions of substituted benzenes with acid chloride or anhydrides proceeded smoothly in the presence of a catalytic amount of novel solid‐supported reagents such as EPZG, EPZ10, EPIC and EPZE. These catalysts are reusable and environmentally friendly.     

The Reduction of Aromatic Oximes to Amines with Borohydride Exchange Resin-Nickel Acetate System

Aromatic oximes were reduced to the corresponding amines with borohydride supported on an ion exchange resin (BER)- nickel acetate in methanol in good yields. The isolation of pure products by simple filtration and evaporation is an important feature of this method.     

Envirocat EPZG,R a New Catalyst for the Conversion of Aldoximes Into Nitriles

The conversion of aldoximes into nitriles was carried out at 100°C in the absence of a solvent using Envirocat EPZG^R as a new solid supported catalyst.     

Efficient and Selective Halogenation of Allylic and Benzylic Alcohols under Mild Conditions

Summary. A simple, mild, and high yielding procedure for the halogenation of allylic and benzylic alcohols using a combination of SOCl₂, benzotriazole, and potassium halides in DMF is described. The effectiveness of the protocol is manifested in its selectivity towards allylic and benzylic alcohols whereas other simple alcohols such as primary, secondary, and tertiary are found to be unreactive.     

ACTIVATION ENERGY OF DESORPTION OF DIBENZOFURAN ON ACTIVATED CARBONS

1. INTRODUCTION With the development of municipalization in China, more and more cities are challenged by the problem of how to dispose of the dramatically increased municipal waste. Generally, most of municipal solid waste is landfilled or dumped openly in the suburbs. It causes not only land waste, but also serious environment pollution. In order to solve efficiently the environment pollution caused by municipal solid waste, incineration technique was introduced in some big cities such…