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Currently threatening the world of medicine is a growing number of antibiotic-resistant diseases. More specifically, bacteria and nematodes have gained resistance to many of the world's leading antibiotics and nematicides, respectively, making infections more difficult to treat. Subsequently, these parasitic organisms are able to continue damaging crops and other living organisms like humans without strong interference. To help people and the environment, the development of new and novel antibiotics is vital. Previous research suggests that phytochemicals are a potential solution that will not only help inhibit bacterial growth but also reduce nematode survival. We hypothesized that Myrica cerifera , a plant often used by the Lumbee tribe to treat illness, possesses antibacterial and nematicidal properties. To answer our hypothesis, we began by collecting plant specimens to extract material for biological assays and to subsequently isolate and elucidate the structures of active components. The extract was evaluated for antibacterial properties with an agar diffusion assay and then nematicidal properties using Caenorhabditis elegans . M. cerifera extract was added onto an agar lawn at various doses, and the nematodes' lifespans were scored. The findings of this study show that extracts of this plant, more commonly referred to as 'wax myrtle', do significantly decrease the lifespan of C. elegans and increase the zone of inhibition for Staphylococcus epidermidis and Staphylococcus aureus . In addition, two compounds were isolated and characterized through chemical extraction, chromatographic separation, and spectroscopic analysis. These compounds could potentially be used to treat bacterial and nematode infections.

Dications of 9-(3-phenyl-1H-inden-1-ylidene)-5H-dibenzo[a,d]cycloheptene, 5(2+), were prepared by oxidation with SbF(5) in SO(2)ClF, and their magnetic behavior was compared to dications of 9-(3-phenyl-1H-inden-1-ylidene)-9H-fluorene, 2(2+). The good correlation between the experimental (1)H NMR shifts for the dications that were oxidized cleanly and the chemical shifts calculated by the GAIO method supported the use of the nucleus independent chemical shifts, NICS, to evaluate the antiaromaticity of the indenyl systems of 2(2+)/5(2+) and their unsubstituted parent compounds, 6(2+) and 7(2+), as well as the antiaromaticity of the fluorenyl system of 2(2+)/7(2+) and the aromaticity of the dibenzotropylium system of 5(2+)/6(2+). Antiaromaticity was shown to be directly related to the amount of charge in the antiaromatic systems, with the antiaromatic systems more responsive to changes in the calculated NBO charge than the aromatic systems. The antiaromaticity was also shown to be directly related to the amount of delocalization in the ring system. The aromaticity of the dibenzotropylium system was much less responsive to changes in the amount of charge in the tropylium system, because the aromatic system was much more completely delocalized. Thus, antiaromatic species are more sensitive probes of delocalization than aromatic ones.

Oxidation of m- and p-substituted benzylidene fluorenes to antiaromatic dications was attempted by electrochemical and chemical means. Electrochemical oxidation to dications was successful for benzylidene fluorenes with p-methoxy, p-methyl, p-fluoro, and unsubstituted phenyl rings in the 3-position; attempts to oxidize the m-substituted derivatives via electrochemistry were unsuccessful. Chemical oxidation with SbF(5)/SO(2)ClF gave the dication of 9-[(4-methoxyphenyl)methylene]-9H-fluorene cleanly; oxidation of all other substituted benzylidene fluorenes resulted in mixtures of products. The excellent linear relationship between the chemical shifts calculated by the GIAO method and the experimental shifts for the p-methoxy-substituted benzylidene fluorene dication suggests that the calculations satisfactorily reflect the magnetic properties of this dication and potentially those of the other dications studied. The redox potentials from electrochemical oxidation, a measure of the stability of the dications, showed a good linear relationship with another measure of stability, the calculated difference in energy between each dication and its neutral precursor. The dications of benzylidene fluorenes were less stable than the dications of diphenylmethylidene fluorenes; within each type of compound, dications with p-substituted phenyl rings were more stable than dications with m-substituted phenyl rings and dications with phenyl rings substituted with electron-donating groups were more stable than dications with phenyl rings substituted with electron-withdrawing groups. The antiaromaticity of the fluorenyl system was assessed through the nucleus-independent chemical shift (NICS) that was also calculated by the GIAO method. The plot of the NICS values per square area versus the calculated energy difference for the dications showed a moderate degree of linearity; the plot of NICS values per square area versus the oxidation potentials was less linear. Thus, a suggestive, but not conclusive, relationship between magnetic and energetic measures of antiaromaticity was observed.

Dications of p-substituted 3-phenylindenylidenefluorenes were prepared to examine the response of the resulting indenyl and fluorenyl cationic systems to magnetic measures of antiaromaticity. All measures, (1)H NMR shifts, nucleus independent chemical shifts (NICS(1)(zz)), and magnetic susceptibility exaltation, Lambda, supported the antiaromaticity of the dications 3a-f2+. The 1H NMR shifts and NICS(1)(zz) showed that the indenyl ring system was less antiaromatic than the fluorenyl ring system, contrary to the antiaromaticity of indenyl monocations compared to fluorenyl monocations. The presence of a phenyl substituent in the 3-position was able to stabilize the indenylidene cation through resonance, decreasing its antiaromaticity, but even in the absence of the 3-phenyl substituent, the indenyl system of indenylidenefluorene dications was less antiaromatic than the fluorenyl system. The decreased antiaromaticity of the 3-phenylindenylidenefluorene dications over the unsubstituted indenylidenefluorene dication was supported by (anti)aromatic (de)stabilization energy calculations, ASE.

[reaction: see text] Electrochemical oxidation of meta-substituted diphenylmethylidenefluorenes (3a-g) results in the formation of fluorenylidene dications that are shown to be antiaromatic through calculation of the nucleus independent chemical shift (NICS) for the 5- and 6-membered rings of the fluorenyl system. There is a strong linear correlation between the redox potential for the dication and both the calculated NICS and sigma(m). Redox potentials for formation of dications of analogously substituted tetraphenylethylenes shows that, with the exception of the p-methyl derivative, the redox potentials for these dications are less positive than for formation of the dications of 3a-g and for dications of p-substituted diphenylmethylidenefluorenes, 2a-g. The greater instability of dications of 2a-g and 3a-g compared to the reference system implies their antiaromaticity, which is supported by the positive NICS values. The redox potentials for formation of the dications of meta-substituted diphenylmethylidenes (3a-g) are more positive than for the formation of dications of para-substituted diphenylmethylidenes (2a-g), indicating their greater thermodynamic instability. The NICS values for dications of 3a-g are more antiaromatic than for dications of 2a-g, which is consistent with their greater instability of the dications of 3a-g. Although the substituted diphenylmethyl systems are not able to interact with the fluorenyl system through resonance because of their geometry, they are able to moderate the antiaromaticity of the fluorenyl cationic system. Two models have been suggested for this interaction, sigma to p donation and the ability of the charge on the substituted ring system to affect delocalization. Examination of bond lengths shows very limited variation, which argues against sigma to p donation in these systems. A strong correlation between NICS and sigma constants suggests that factors that affect the magnitude of the charge on the benzylic (alpha) carbon of the diphenylmethyl cation affect the antiaromaticity of the fluorenyl cation. Calculated atomic charges on carbons 1-8 and 10-13 show an increase in positive charge, and therefore greater delocalization of charge in the fluorenyl system, with increasing electronegativity of the substituent. The change in the amount of positive charge correlated strongly with NICS, supporting the model in which the amount of delocalization of charge is related to the antiaromaticity of the species. Thus, both aromatic and antiaromatic species are characterized by extensive delocalization of electron density.

[reaction: see text] N-Monosubstituted carbamates are cleanly converted to amides under treatment with trialkylaluminum. This reaction involves an aluminum-assisted internal delivery of alkyl groups. It can be applied to new and mild protecting group strategies for alcohols.

Trimethylaluminum addition to N-monoalkyl or N-monoaryl hydrazones followed by aldehyde addition leads to the formation of N-alkylated hydrazones in a new formal Mannich-type process. Addition compounds were also obtained in moderate yields with ketones. The mechanism as well as possible intermediates involved in the reaction are discussed.

1,2,3,4-tetraphenyl-1,2-dihydrodiphosphetene 1 reacts with lithium or sodium naphthalenide to afford the corresponding dianionic salts 2 and 3. An X-ray crystal structure analysis shows that dianion 3 of general formula [(1)2-2Na3(DME)2, Na(DME)3] is a polymeric structure consisting of [(1)2-2Na3(DME)2] units which are connected together through one sodium atom. Reaction of the dianionic lithium salt 2 with [Pt(COD)Cl2] affords the 4[Li(2.2.1)]2 complex, after the addition of 2 equiv of (2.2.1) cryptate. The overall geometry around platinum in 4[Li(2.2.1)]2 can be described as distorted square planar, and only the diastereomer (1-R, 2-S, 3-R, 4-S) is formed. X-ray data indicate that no delocalization takes place within each platinadiphospholene unit and that complex 4[Li(2.2.1)]2 must be regarded as the coordination of two molecules of dianion 2 onto a Pt2+ center. Reaction of the dianionic sodium salt 3 with 1 equiv of [Pt(COD)Cl2] produces the 4[Na(DME,Et2O)]2 complex which adopts a pseudotetrahedral geometry around platinum ( between interplane angles = 35), the two cationic units [Na(DME, Et2O)] being located along a C2 axis. Four weak interactions exist between the sodium cations and the phosphorus atoms. Only the (1-S, 2-S, 3-S, 4-S) diastereomer is formed. Bond distances in the diphospholene units of 4[Na(DME,Et2O)]2 are close to that of dianion 3 indicating that, like in 4[Li(2.2.1)]2, the complex can be described as a platinum (+2) dianionic species.