Formal aza-Michael additions to tropone: Addition of diverse aryl- and alkylamines to tricarbonyl(tropone)iron and [(C7H7O)Fe(CO)3]BF4

Crystal structure of tricarbon-yl[η4-6-exo-(tri-phenyl-phosphino)cyclo-hepta-2,4-dien-1-one]iron(0) tetra-fluoro-borate

The mol-ecular structure of tricarbon-yl[η4-6-exo-(tri-phenyl-phosphino)cyclo-hepta-2,4-dien-1-one]iron(0) tetra-fluoro-borate di-chloro-methane hemisolvate, [Fe(C28H22O4)(CO)3]BF4·0.5CH2Cl2, as determined by single-crystal X-ray diffraction is reported. The two independent tricarbon-yl[η4-6-exo-(tri-phenyl-phosphino)cyclo-hepta-2,4-dien-1-one] iron(0) cations and their corresponding anions form dimers, which constitute the asymmetric unit of the structure parallel to the (100) plane. Solid-state stability within that asymmetric unit as well as between neighboring dimeric units is afforded by C-H⋯O and C-H⋯F hydrogen bonds and C-H⋯π and Y-X⋯π (Y = B, C; X = F, O) inter-actions, which yield diperiodic sheets and a three-dimensional extended network.

Synthesis of 7-azabicyclo[4.3.1]decane ring systems from tricarbonyl(tropone)iron via intramolecular Heck reactions

The 7-azabicyclo[4.3.1]decane ring system, common to a number of biologically active alkaloids, was accessed from tropone (via its η4-diene complex with Fe(CO)3) in a short sequence of steps: 1) nucleophilic amine addition and subsequent Boc-protection, 2) photochemical demetallation of the iron complex, and 3) an intramolecular Heck reaction. Minor modifications to the protocol enabled access to the related 2-azabicyclo[4.4.1]undecane system, albeit in lower yield.

Sodium Trifluoroacetate mediated Copper-Catalyzed aza-Michael addition of α,β-unsaturated olefins with aromatic amines

We present a sodium trifluoroacetate (CF3CO2Na) mediated copper-catalyzed aza-Michael addition of aromatic amines with activated olefins under mild, aqueous reaction conditions. This simplistic protocol employs a copper catalyst (10 mol%) and water as solvent. This transformation occurs precisely with aromatic substituted amines containing both electron-donating (EDG) and electron-withdrawing (EWG) groups. A broad range of substrates were tested under the optimized conditions, which are producing good to moderate yields.

Synthetic Entry to the 2-Azatricyclo[4.3.2.04,9]undecane Ring System via Tropone

A synthesis of the 2-azatricyclo[4.3.2.0^4,9]undecane ring system-a hitherto unreported bridged azatricyclic ring system-beginning from tricarbonyl(tropone)iron and allylamine was accomplished in three steps: (1) aza-Michael addition of allylamine to tricarbonyl(tropone)iron; (2) Boc-protection of the resulting secondary amine; and (3) oxidative demetallation leading to a spontaneous intramolecular Diels-Alder reaction. The effect of a variety of parameters on the intramolecular Diels-Alder reaction was investigated, including diene and dienophile substitution patterns and dienophile tether length.