Preparation and Application of Iron-substituted (Z)-Enals: Synthesis of 5-Substituted α,β-Butenolides

ChemInform Abstract: Organoiron Compounds for Selective Organic Transformations

ChemInform Abstract: Rare Earth Metal Catalysts

Reactions of (η5-C5H5)(CO)2Fe-Substituted N-Sulfonyl Azadienes with C-Nucleophiles. A Route to 5-Substituted Dihydropyrrolones

A variety of cyclic β-[(η5-C5H5)(CO)2Fe]-substituted N-sulfonyl azadienes 4 were prepared:  e.g., from the corresponding iron-substituted (Z)-enals and benzenesulfonamide. Reactions of these iron compounds with Grignard reagents or organolithiums gave 5-substituted α,β-unsaturated N-sulfonyl γ-lactams 5. In some cases the corresponding non-N-protected 5-substituted γ-lactams 6 were isolated as well. Key steps of these reaction cascades are the initial 1,2-addition to the imine moiety and the subsequent carbonylation step. The reaction of the chromene−iron complex 4e with (allyl)MgCl gave the (η3-allyl)iron−γ-lactam complex 8a with a ring-opened chromene framework. This complex was structura…

Rare Earth Metal Catalysts

ChemInform Abstract: Reactions of (η5-C5H5) (CO)2Fe-Substituted N-Sulfonyl Azadienes with C-Nucleophiles. A Route to 5-Substituted Dihydropyrrolones.

A Novel Approach to Dihydropyrrolones from Iron-Substituted α,β-Unsaturated Imines and Organolithium and Grignard Reagents: Developments, Mechanisms and Stereoselective Syntheses

Reactions of N-sulfonylimines, derived from Cp(CO)2Fe-substituted (Z)-enals and benzenesulfonamide, with Grignard or organolithium reagents furnish N-sulfonyldihydropyrrolones. When N-sulfinylimines and organometallic reagents are used, unprotected α,β-unsaturated γ-lactams are formed exclusively. Recent mechanistic studies and diastereoselective variations for the synthesis of chiral 5-substituted dihydropyrrolones from iron-substituted azadienes are discussed here.

ChemInform Abstract: Preparation and Application of Iron-Substituted (Z)-Enals: Synthesis of 5-Substituted α,β-Butenolides.