Formamidines diaryl

Formamidine, N,N -di-2-anthraquinonyI-metal complexes, 2,275 Formamidine, IV.AT-diaryl-metal complexes, 2, 275 Formamidine, N, N -dibenzyl-metal complexes, 2,276 Formamidine, IV.N -diisopropyl-metal complexes, 2, 276 Formamidinesulfinic acid technetium complexes, 6, 974 Formate dehydrogenases bacteria... 

Wahrend N,N -disubstituierte Harnstoffe von Lithiumalanat nicht angegriffen werden, erhalt man mit Natriumboranat in siedendem Pyridin mit mittleren Ausbeuten die entsprechenden N,N -disubstituierten Formamidine. N,N -Dialkyl-harnstoffe liefern die besten Ausbeuten, N,N -Diaryl-harnstoffe die schlechtesten3. 

It was shown in separate experiments that anilines can react with formamidines to give both N-mono- and N,N-diaryl formamidines which no longer are effective inhibitors. Another way of modifier deactivation is the hydrolysis to ineffective formamide by water formed during the hydrogenation of the nitro group. This could explain the rather high modifier concentration needed in order to get good selectivities. Similar observations of instability under reaction conditions have also been reported for dicyandiamide (ref. 4). 

---