PREPARATION AND REACTIVITIES OF (ETA-3-1-AND 2-TRIMETHYLSILOXYALLYL)FE(CO)2NO COMPLEXES - INTERMEDIATES FUNCTIONING AS EQUIVALENTS OF BETA-ACYL AND ALPHA-ACYL CARBOCATIONS AND ACYL CARBANIONS

(eta-3-1- and 2-Trimethylsiloxyallyl)Fe(CO)2NO complexes were prepared by the reaction of the corresponding siloxyallylic halides with Bu4N[Fe(CO)3NO]. These complexes reacted with both of carbon nucleophiles and carbon electrophiles preferentially at the less hindered sites of the allylic ligands. In these reactions, (eta-3-1-trimethylsiloxyallyl)Fe(CO)2NO complexes served as synthetically equivalent synthons for both of beta-acyl carbocations and beta-acyl carbanions and (eta-3-2-trimethylsiloxyallyl)Fe(CO)2NO complexes as both of alpha-acyl carbocations and alpha-acyl carbanions. The stereochemical courses of the reactions are described.