Organocatalyzed Enantioselective Formal [4 + 2] Cycloaddition of 2,3-Disubstituted Indole and Methyl Vinyl Ketone

A formal [4 + 2] cycloaddition of 2,3-disubstituted indoles with vinyl methyl ketone was realized in the presence of a catalytic amount of quinine-derived primary amine and pentafluorobenzoic acid. This method provides bridged-ring indoline scaffolds containing two quaternary carbon centers with excellent yields and enantioselectivity (up to 98% yield and 98% ee)

'Systema morborum'

Enantioselective construction of pyrroloindolines <i>via</i> chiral phosphoric acid catalyzed cascade Michael addition–cyclization of tryptamines has been realized. With 5 mol % of chiral phosphoric acid, enantioenriched pyrroloindoline derivatives were obtained in good yields and enantioselectivity (up to 95% yield and 83% ee) from readily available tryptamines and enones

Total Synthesis of Trioxacarcins DC-45-A1, A, D, C, and C7″-<i>epi</i>-C and Full Structural Assignment of Trioxacarcin C

Trioxacarcins DC-45-A2, DC-45-A1, A, D, C7″-<i>epi</i>-C, and C have been synthesized through stereoselective strategies involving BF₃·Et₂O-catalyzed ketone–epoxide opening and gold-catalyzed glycosylation reactions, and the full structural assignment of trioxacacin C was deciphered via the syntheses of both of its C7″ epimers. The gathered knowledge sets the foundation for the design, synthesis, and biological evalution of analogues of these natural products as potential payloads for antibody–drug conjugates and other delivery systems for targeted and personalized cancer chemotherapy

Enantioselective Synthesis of Inherently Chiral Calix[4]arenes via Palladium-Catalyzed Asymmetric Intramolecular C–H Arylations

We report herein an efficient approach for the enantioselective synthesis of inherently chiral calix[4]arenes via palladium-catalyzed asymmetric intramolecular C–H arylations. Using a chiral bifunctional phosphine-carboxylate ligand, the inherent chirality on macrocyclic scaffolds was induced successfully, from which a wide range of calix[4]arenes with fluorenone motifs were obtained with good yields and excellent enantioselectivities (up to >99% ee). The synthetic utility of this method was demonstrated by diverse transformations of the products, thus substantially expanding the chemical space of chiral calix[4]arenes. Further investigations of photophysical and chiroptical properties revealed that calix[4]arenes bearing two fluorenone moieties displayed remarkable glum values (up to 0.019), highlighting the great potential of inherent chirality in the development of organic optoelectronic materials

General Synthetic Approach to Functionalized Dihydrooxepines

A three-step sequence to access functionalized 4,5-dihydrooxepines from cyclohexenones has been developed. This approach features a regioselective Baeyer–Villiger oxidation and subsequent functionalization via the corresponding enol phosphate intermediate

Cr(VI) Adsorption and Reduction by Humic Acid Coated on Magnetite

Easily separable humic acid coated magnetite (HA-Fe₃O₄) nanoparticles are employed for effective adsorption and reduction of toxic Cr­(VI) to nontoxic Cr­(III). The adsorption and reduction of Cr­(VI) is effective under acidic, neutral, and basic pH conditions. The chromium adsorption nicely fits the Langmuir isotherm model, and the removal of Cr­(VI) from aqueous media by HA-Fe₃O₄ particles follows pseudo-second-order kinetics. Characterization of the Cr-loaded HA-Fe₃O₄ materials by X-ray absorption near edge structure spectroscopy (XANES) indicates Cr­(VI) was reduced to Cr­(III) while the valence state of the iron core is unchanged. Fe <i>K</i>-edge extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray diffraction measurements also indicate no detectable transformation of the Fe₃O₄ core occurs during Cr­(VI) adsorption and reduction. Thus, suggesting HA on the surface of HA-Fe₃O₄ is responsible for the reduction of Cr­(VI) to Cr­(III). The functional groups associated with HA act as ligands leading to the Cr­(III) complex via a coupled reduction–complexation mechanism. Cr <i>K</i>-edge EXAFS demonstrates the Cr­(III) in the Cr-loaded HA-Fe₃O₄ materials has six neighboring oxygen atoms likely in an octahedral geometry with average bond lengths of 1.98 Å. These results demonstrate that easily separable HA-Fe₃O₄ particles have promising potential for removal and detoxification of Cr­(VI) in aqueous media

Ring-Closing Metathesis/Isomerization/Pictet–Spengler Cascade <i>via</i> Ruthenium/Chiral Phosphoric Acid Sequential Catalysis

Chiral phosphoric acid worked together with Hoveyda–Grubbs II catalyst enabling highly efficient synthesis of enantioenriched tetrahydro-β-carbolines (up to 98% yield, 99% ee) through a ring-closing metathesis/isomerization/Pictet–Spengler cascade reaction <i>via</i> sequential catalysis

Streamlined Total Synthesis of Trioxa­carcins and Its Application to the Design, Synthesis, and Biological Evaluation of Analogues Thereof. Discovery of Simpler Designed and Potent Trioxa­carcin Analogues

A streamlined total synthesis of the naturally occurring antitumor agents trioxa­carcins is described, along with its application to the construction of a series of designed analogues of these complex natural products. Biological evaluation of the synthesized compounds revealed a number of highly potent, and yet structurally simpler, compounds that are effective against certain cancer cell lines, including a drug-resistant line. A novel one-step synthesis of anthra­quinones and chloro anthra­quinones from simple ketone precursors and phenyl­selenyl chloride is also described. The reported work, featuring novel chemistry and cascade reactions, has potential applications in cancer therapy, including targeted approaches as in antibody–drug conjugates

Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas-0

<p><b>Copyright information:</b></p><p>Taken from "Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas"</p><p>http://www.translational-medicine.com/content/5/1/67</p><p>Journal of Translational Medicine 2007;5():67-67.</p><p>Published online 19 Dec 2007</p><p>PMCID:PMC2254376.</p><p></p>that were not stimulated with the type-1 cytokine-mixture (standard DCs). This was done with 24 hr stimulation of DCs (20 × 10per well, duplicates) with CD40L-transfected J558 cells (50 × 10per well). Supernatant was harvested and the production of IL-12 p70 was assayed by specific ELISA. Values indicate averages of duplicate samples. Bars indicate standard errors

Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas-2

<p><b>Copyright information:</b></p><p>Taken from "Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas"</p><p>http://www.translational-medicine.com/content/5/1/67</p><p>Journal of Translational Medicine 2007;5():67-67.</p><p>Published online 19 Dec 2007</p><p>PMCID:PMC2254376.</p><p></p> by a neuroradiologist