A Novel Cathode Material for Cathodic Dehalogenation of 1,1‐Dibromo Cyclopropane Derivatives

Leaded bronze turned out to be an excellent cathode material for the dehalogenation reaction of cyclopropanes without affecting the strained molecular entity. With this particular alloy, beneficial properties of lead cathodes are conserved, whereas the corrosion of cathode is efficiently suppressed. The solvent in the electrolyte determines whether a complete debromination reaction is achieved or if the process can be selectively stopped at the monobromo cyclopropane intermediate. The electroorganic conversion tolerates a variety of functional groups and can be conducted at rather complex substrates like cyclosporine A. This approach allows the sustainable preparation of cyclopropane derivatives.     

Synthesis,electrochemical properties and fungicidal activity of 1,1′‐bis(aroyl)ferrocenes and their derivatives

Reaction of functionalized cyclopentadienyl sodium CH₃O₂CArC(O)CpNa (Ar = aryl and Cp = cyclopentadienyl) with FeCl₂ in a 2:1 ratio gives 1,1′‐bis(aroyl)ferrocenes [CH₃O₂CArC(O)Cp]₂Fe in reasonable yields. Upon treatment of these aroyl compounds with NaBH₄, the ketone carbonyl is reduced to yield compounds [CH₃O₂CArCH(OH)Cp]₂Fe, while with the stronger reductive reagent LiAlH₄, diols [HOCH₂ArCH(OH)Cp]₂Fe are obtained. All new compounds were characterized by IR and NMR spectroscopic analyses. Their electrochemical behavior was investigated by cyclic voltammetry. The structure of [CH₃O₂CC₁₀H₆C(O)Cp]₂Fe was further confirmed by single crystal X‐ray diffraction analysis. In addition, the fungicidal activities of these new compounds were also determined in vitro. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and Herbicidal Activities of Novel 3‐(α‐Hydroxymethylene) pyrrolidine‐2,4‐dione Derivatives Containing a Cyclopropane Moiety

A variety of novel 3‐(α‐hydroxymethylene)pyrrolidine‐2,4‐dione derivatives containing a cyclopropane moiety were designed and synthesized in satisfactory yields. Their structures were confirmed by ¹H NMR and HRMS. The bioassays indicated that most of the title compounds displayed some extent herbicidal activities at 100 mg/mL.     

Synthesis of Novel Series of 6‐Chloro‐1,1‐dioxo‐1,4,2‐benzodithiazine Derivatives with Potential Biological Activity

A series of 6′‐chloro‐1′,1′‐dioxo‐2′H‐spiro[benzo[d][1,3,7]oxadiazocine‐4,3′‐(1,4,2‐benzodithiazine)]‐2,6(1H,5H)‐dione derivatives 2a , 2b and 3a , 3b have been synthesized starting from 3‐aminobenzodithiazines 1a , 1b and isatoic anhydride. Subsequent reactions of 2a with 3‐chlorophenyl isocyanate gave condensation products 4 and 5 . Compound 2a was also converted into 3‐(2‐aminobenzamido)‐6‐chloro‐7‐methyl‐1,1‐dioxo‐1,4,2‐benzodithiazine derivatives 6 , 7 , 8 , 9 , 10 . The mechanisms of the reactions are discussed.     

A Vibrational Raman Optical Activity Study of 1,1′‐Binaphthyl Derivatives

The Raman polarized and vibrational Raman optical activity (VROA) backward spectra are simulated for a series of 2,2′‐substituted 1,1′‐binaphthyl compounds presenting a variety of torsion angles between the two naphthalene rings. The substitution prevents free rotation along this torsion angle and the chirality of these compounds is thus called atropisomerism. However, the rotation is not completely frozen so that two different conformations, namely cisoid and transoid, are found and their Raman and VROA signatures are studied. As expected, the Raman spectra are not very sensitive whereas the VROA spectra present more complex patterns, which evolve as a function of the torsion angle between the two naphthalene groups. In particular, our analysis shows that some modes can be used as a probe for the determination of the torsion angle of these molecules in solution. The contributions of both invariants to the VROA backward intensity are also assessed.