Preparation and Reactivities of (η3-1- and 2-Trimethylsiloxyallyl)Fe(CO)2NO Complexes. Intermediates Functioning as Equivalents of β- and α-Acyl Carbocations and Acyl Carbanions

Abstract

(η3-1- 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, (η3-1-trimethylsiloxyallyl)Fe(CO)2NO complexes served as synthetically equivalent synthons for both of β-acyl carbocations and β-acyl carbanions and (η3-2-trimethylsiloxyallyl)Fe(CO)2NO complexes as both of α-acyl carbocations and α-acyl carbanions. The stereochemical courses of the reactions are described.