Carbonyliron Complexes of Allenic Acids,Esters, Amides,and Imides

On irradiation in the presence of Fe(CO)₅, the allenic amides and imides showed a similar course of complexation to that of esters and lactones, respectively, e.g. the amides of type 10 led to diiron complexes of type 11 (Scheme 3), whereas the imide 12 yielded a mixture of a dinuclear and two mononuclear complexes ( 13–15 , Scheme 4). The racemic ester 6 also gave mononuclear ( 7a , 7b , and 9 ) and dinuclear complexes (8 a and 8b ; Scheme 2). In case of the allenic acid 4 , only complexation of type 5 was observed (Scheme 1).