Structures of cabenegrins A-I and A-II,potent anti-snake venoms

Two potent antidotes against snake venoms have been isolated from the aqueous ethanol extract of a South American plant. The structures have been determined to be $\text{1}$ and $\text{2}$.     

Dihalogenphosphankomplexe als metallorganische synthesebausteine

The dichlorophosphanes (R)P(Cl)₂ react with Fe₂(CO)₉ to give (CO)₄FeP(R)(Cl)₂ (I) in high yields. When treated with Fe₂(CO)₉ in 2.5 M excess, compounds I give the μ₂-chloro-μ₂-chlorophosphido-bridged dinuclear molecules II, Fe₂(CO)₆(μ₂Cl)(μ₂-PRCl). Further treatment of II with Fe₂(Co)₉ results in the formation of the trinuclear clusters IV, Fe₃(CO)₁₀(μ₃-PR). Zinc reduction of II leads to V, Fe₄(CO)₁₁(μ₄-PR)₂. All of these reactions lead to fairly high yields for a variety of substituents R. The product selectivity is effectively controlled by the stoichiometry. The syntheses and properties of the main products I, II, IV and V, as well as those of the dinuclear side-products [(CO)₂(Cl)(RPCl₂)Fe(μ₂-PRCl)]₂ (III), [(CO)₃Fe(μ₂-PRCl)]₂ (VI), and the trinuclear species (CO)₉Fe₃(μ₃-PR)₂ (VII), are discussed.