Ether as Alkylating Agent

On the left of the chromatogram is depicted the analysis of the reaction mixture obtained with racemic a-methylbenzylamine two groups of two peaks corresponding to the two enantiomeric forms of both the starting material and the reaction product are observed. The right of the chromatogram shows the results 

We have shown that N-alkylation of amines by aleohols in the gas-phase over y-alumina is possible for a wide range of amines (aliphatic or aromatic) and alcohols (from methanol to hexanol). We have also proved that ethers can be used as alkylating agents. This last point is of practical interest because separation of the polar amine from the non-polar ether solvent is easier than from the polar alcohol. Above all, we have clearly demonstrated that chirality is compatible with gas-phase conditions and thus proposed a selective new method for mono-N-alkyla-tion and, in particular, for methylation of chiral amines. This opens new perspectives for gas-phase heterogeneous catalysis. 

Roger Arthur Sheldon, Herman van Bekkum copyright WILEY VCH Verlag GmbH, 2001 

Olefin epoxidation is not only important in the manufacture of bulk chemicals, e. g. ethylene and propylene oxides, but is also a widely used transformation in the fine-chemicals industry [1], Ethylene oxide is manufactured by vapor-phase oxidation of ethylene, with air or oxygen, over a supported silver catalyst [2], This method is not generally applicable as olefins containing allylic or other reactive C-H bonds give complex mixtures of products with low epoxide selectivity. The method has recently been extended to some other olefins that do not contain reactive allylic C-H bonds, e. g. butadiene, styrene, norbornene, and tert-butyl ethylene [3]. Some of these products, e. g. butadiene monoepoxide and styrene oxide, have potential applications as fine chemicals/intermediates. 

In this review we shall focus on the use of heterogeneous catalysts for the liquid phase epoxidation of olefins with alkyl hydroperoxides or hydrogen peroxide. The latter is generally the oxidant of choice for fine-chemicals production owing to a better availability and lower price. Emphasis is placed on methods with a broad scope in organic synthesis. 

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