Direct synthesis of highly substituted 2cyclohexenones and sterically hindered benzophenones based on a 5C 1C annulation
The regiospecific [5C + 1C] annulation of readily available alpha-alkenoyl ketene (S,S)-acetals 1 with aryl methyl ketones 2, the less active methylene compounds, has been developed. Upon treatment of 1 with 2 in the presence of t-BuOK in DMF at room temperature, highly substituted 2-cyclohexenones 3 were synthesized in high to excellent diastereoselectivities with high yields. On the basis of this strategy, sterically hindered benzophenones 4 were conveniently MeONa/MeOH basic medium. Furthermore, benzophenones 4 were also obtained directly from 1 and 2 following a sequential [5 + 1] annulation-iodonation-aromatization procedure in a one-pot operation.A highly efficient biomimetic aromatization of Hantzsch-1,4-dihydropyridines with t-butylhydroperoxide, catalysed by iron(III) phthalocyanine chloride.Rapid aromatization of Hantzsch-1,4-DHPs with t-butylhydroperoxide catalysed by iron(III) phthalocyanine chloride is described.
The reaction proceeds smoothly at room temperature within 1-35 min and the products of high purity were isolated in excellent yields. To explain the reactivity of this catalytical system plausible mechanism have been proposed to involve formation of high-valent oxoferryl species as in cytochrome P450 itself.Stereoselective inhibition of aromatase by enantiomers of aminoglutethimide.The dextrorotatory enantiomer of aminoglutethimide is 38 times more potent than the levoenantiomer in inhibiting aromatization of testosterone by human placental microsomes. The spectral affinity constant for microsomal cytochrome P-450 is 36 times greater for the d-enantiomer. Enzymatic inhibition and affinity are highly correlated for each of the isomers as well as for the racemic mixture. Spectral analysis of the interactions of the inhibitors with the substrate supports the evidence for participation of cytochrome P-450 in Cleanroom strategies for micro- and nano-fabricating flexible implantable neural Implantable electronic neural interfaces typically take the form of probes and are made with rigid materials such as silicon and metals.
These have advantages such as compatibility with integrated microchips, simple implantation and high-density nanofabrication but tend to be lacking in terms of biointegration, biocompatibility and durability due to their mechanical rigidity. This leads to damage to the device or, more importantly, the brain tissue surrounding the implant. Flexible polymer-based probes offer superior biocompatibility in terms of surface biochemistry and better matched mechanical properties. Research which aims to bring the fabrication of electronics on flexible polymer substrates to the nano-regime is remarkably sparse, despite the push for flexible consumer electronics in the last decade or so. Cleanroom-based nanofabrication techniques such as photolithography have been used as pattern transfer methods by the semiconductor industry to produce single nanometre scale devices and are now also used for making flexible circuit boards. There is still much scope for miniaturizing flexible electronics further using photolithography, bringing the possibility of nanoscale, non-invasive, high-density flexible neural interfacing. This work explores the fabrication challenges of using photolithography and complementary techniques in a cleanroom for producing flexible electronic neural probes with nanometre-scale features.
6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid in Electrophilic Aromatic Substitution is part of the theme issue 'Advanced neurotechnologies: translating innovation for Incorporating Photochromic Viologen Derivative to Unprecedentedly Boost UV Sensitivity in Photoelectrochromic Hydrogel.Applied Physics, Chinese Academy of Sciences, 2019 Jia Luo Road, Shanghai Beijing University of Chemical Technology, North Third Ring Road 15, Chaoyang Developing ultraviolet (UV) radiation sensors featuring high sensitivity, ease of operation, and rapid readout is highly desired in diverse fields. However, the strategies to enhance sensitivity of UV detection remain limited particularly for photochromic materials, which show colorimetric response toward UV irradiation. Guided by our initial goal of facilitating easier handling, we formulated a viologen derivative ([H2L]-SC) incorporating hydrogel-based UV sensor which not only inherits the photochromism of [H2L]-SC but also engenders an unprecedented reversible photoelectrochromic response that is absent in either [H2L]-SC or hydrogel alone. Judicious synergy between photochromic [H2L]-SC and polyacrylamide (PAM) converts the colorimetric response of [H2L]-SC sensitivity of [H2L]-SC by 2 orders of magnitude. Explicitly, the limit of detection (LOD) for UV decreases from 296 mJ/cm2 based on the UV-vis absorption spectra of [H2L]-SC to 23 mJ/cm2 derived from the resistance as a dual platform for quantifying both the accumulated UV dose and the instant dose rate. In addition, the proposed strategy based on constructing photoelectrochromic hybrids offers a new pathway to boost the UV sensitivity that could be universal for other photochromic materials.
Synthesis of 6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid and its Variants : field evaluation in the northern Gulf of Chekalyuk A, Barnard A, Quigg A, Hafez M, Zhao Y.
