N acyl a arylenamides

The accessibility of prochiral precursors is a key factor to a successful hydrogenation process from a practical point. There are several common and efficient methods for the formation of various enamides. An example is the preparation of N acyl a arylenamides as illustrated in Scheme 9.2. 

Scheme 9.2 General methods for the synthesis of N acyl a arylenamides.

The present methods for the preparation of N acyl a arylenamides include (i) reductive acylation of ketoximes with iron metal [2] or phosphines [3] in the presence of acyl chlorides or acyl anhydrides (Method A) (ii) metal catalyzed coupling of vinyl halides [4], triflates [5], or tosylates [6] with amides (Method B) (iii) reaction of imine intermediates derived from nitriles with acyl chlorides or anhydrides (Method C) [7] and(iv) Pd catalyzed coupling ofaryl tosylates with N acyl vinylamines (MethodD) [8]. 

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