Carbon-nitrogen bonds catalyst selection

Iron salts have recently attracted considerable attention as inexpensive and environmentally friendly agents in a wide range of selective processes in organic synthesis. Over the past decade, FeCls 6H2O has shown to be an effective catalyst in the formation of carbon-carbon or carbon-nitrogen bonds, in intramolecular Friedel-Craft reactions and in the reduction of ketones or allylic alcohols. ... 

The carbon-nitrogen double bond of phenanthridine can be reduced selectively by hydrogenation over Raney nickel, and attempted reductive dechlorination of 6-chloro derivatives in the presence of this catalyst normally results in the formation of the corresponding 5,6-dihydro compounds.106 Hydrogenations over palladium catalysts are more successful.203 325 Desulfurization of phenanthridinthione... 

This approach should be useful in determining the direction of hydrogenation for molecules in which the carbinol group is replaced by carbon-carbon or carbon-nitrogen double bonds. With an alkene, though, the simple conformational model would have to be used and the hydrogenation should be run under conditions that do not promote double bond isomerization, that is, not with palladium or nickel catalysts. With carbonyl compounds the preferred eonditions for selective reaction involve platinum, rhodium or ruthenium catalysts imder non-diffusion control conditions. The use of nickel catalysts, especially Raney nickel, with its basic components, can cause an equilibration of the alcohol product. 

From Iron(III) Tetraarylporphyrins and Alkenes. N-alkyl porphyrins are formed via side reactions of the normal catalytic cycle of cytochromes P-450 with terminal alkenes or alkynes. N-alkylpor-phyrins formed from terminal alkenes (with model iron porphyrin catalysts under epoxidation conditions) usually have a covalent bond between the terminal carbon atom of the alkene and a pyrrole nitrogen. The double bond is oxidized selectively to an alcohol at the internal carbon. Mansuy (23) showed that, in isolated examples, terminal alkenes can form N-alkylated products in which the internal carbon is bound to the nitrogen and the terminal carbon is oxidized to the alcohol. Internal alkenes may also form N-alkyl porphyrins (24, 25). 

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