Tricarbonyliron complexes rearrangement

In accordance with FMO theory predictions,273 C2 —C4is the preferred modeofcycloaddition of tricarbonyliron and -ruthenium complexes of methyl l//-azepine-l-carboxylate with ethenetetracarbonitrile,222,274 hexafluoroacetone,222 and 2,2-bis(trifluoromethyl)ethene-l,l-dicarbonitrile 222 however, with ethenetetracarbonitrile, tricarbonyl[f/4-l-(ethoxycarbonyl)-1/f-azepine]iron(0) (1) yields a 1 6 mixture of the predicted C2 —C4 exo-adduct 2 and the C2 — C7 [6 + 2] 7i-cycloadduct 3,222 the latter heing formed by rearrangement of the former.274 Mixtures of the two adducts are also obtained with the tricarbonyliron complexes of 3-acetyl-l//-azepine and its l-(ethoxycarbonyl) derivative.274... 

The method involves a highly enantioselective rearrangement of an epoxide and a subsequent Ireland-Claisen rearrangement (see Scheme 31). The enolate Claisen rearrangements of [4-7-//4-4-( 1 -acyloxy-2,4,6-octatrienyl)]tricarbonyliron complexes... 

Photochemical Complexation. The studies of Birch et al. on the thebaine modification using tricarbonyliron complexes exemplify the possibility of complexation of 1,3-dienes by photolysis, and illustrate the potential for iron complexes to ensure control of skeletal rearrangement. Thus, via the initial step of complexation of the methoxycyclohexadiene ring of thebaine (13), practically quantitative access to northebaine (14) and 14a-substituted the-... 

Carbon disulfide complexes of iron 14 are obtained in the reaction of (benzylideneacetone)-tricarbonyliron (o) with P(OMe)3 in carbon disulfide. The complexes react with acetylenes to form iron-carbene complexes 15 ". Depending on the phosphorous ligands, rearrangement to give 16 is observed... 

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