Organoiron complex

Organoiron complexes (7) are converted in high yield into ammonium salts (8) these in turn undergo oxidatively induced ligand transfer and cyclization to give azetidinones (9) in moderate yields (Scheme 9). Formation of the trans product (9b) indicates a stereochemical sequence of trans addition to the olefin complex followed by carboxamidation with retention of configuration at the C—Fe bond. 

The procedure given here illustrates the use of readily prepared organoiron complex 1 for the vinylation of a secondary enolate. This salt may be prepared on a large scale from readily available starting materials and can... 

Si-Lactams. The synthesis of /5-lactams employing organoiron complexes as intermediates (8, 454-455) has been extended to the preparation of bicyclic lactams, in particular to the new carbopenams. A synthesis of 2-methylcarbopenam (1) is shown in equation (I). 

Cyclizations of alkenic amines and imines using organoiron complexes to generate bicyclic 3-lactams are discussed in Chapter 3.1 of this volume. Examples of heterocyclizations of alkenic NA/-dialkylamine and pyridine derivatives to form cyclic quaternary ammonium salts are cited in the Staninets review.Ic A cyclization of an enol thioether has been used to generate a thiazolidine intermediate used in cephalosporin synthesis (equation 131).262... 

In order to understand catalytic systems based on iron, the chemistry of organoiron complexes is briefly described and their reactivity is demonstrated. A comprehensive summary of the applications of iron compounds in organic synthesis has been given by Pearson [7]. 

Pentacarbonyliron is a stable 18-electron complex of trigonal-bipyramidal geometry and represents the primary source of most organoiron complexes. Nonacarbonyldiiron is prepared in a photolytic reaction from pentacarbonyliron. Dodecacarbonyltriiron can be obtained from nonacarbonyldiiron by a thermal reaction. Both, nonacarbonyldiiron and dodecacarbonyltriiron, contain metal-metal bonds. They are slowly degraded to give pyrophoric iron and therefore should be handled with care. 

Organogermanium chlorides have also been utilized as ligands in a number of organoiron complexes (7, 8, 35) and the structures of these compounds are discussed in the context of the Ge—Fe bond (see Section VII). 

Organoiron complexes as potential reagents in organic synthesis. (M. Rosenblum, Accounts Chem. Res., 1974, 7, 122). 

Certain classical coordination complexes (see Coordination Complexes) of iron (e.g. Prussian blue) will be dealt with in other articles (see Iron Inorganic Coordination Chemistry and Cyanide Complexes of the Transition Metals), as will much of the chemistries of iron carbonyls (see Metal Carbonyls) and iron hydrides (see Hydrides) (see Carbonyl Complexes of the Transition Metals Transition Metal Carbonyls Infrared Spectra, and Hydride Complexes of the Transition Metals). The use of organoiron complexes as catalysts (see Catalysis) in organic transformations will be mentioned but will primarily be covered elsewhere (see Asymmetric Synthesis by Homogeneous Catalysis, and Organic Synthesis using Transition Metal Carbonyl Complexes). 

The reaction with Fc3(CO)i2, however, results in the loss of tellurium and formation of tellurium-lfee organoiron complexes. Similar loss of tellurium has reported on the reaction with tellurophenes and benzotellurophenes. " ... 

Pearson and Ong86 have extended their route to trichothecane sesquiterpenoids via organoiron complexes by the synthesis of (144) (Scheme 14). The Diels-Alder approach to the construction of the cw-fused AB ring junction of the tricho-thecanes has been much in evidence. The use of methyl coumalate (145) as a... 

By using the reducing capability of enneacarbonyldiiron, several organoiron complexes have been prepared by dehalogenation. For example, treatments of enneacar-... 

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