Fe-Catalyzed Reductive Coupling of Unactivated Alkenes with β‑Nitroalkenes

An Fe-catalyzed reductive coupling of unactivated alkenes with β-nitroalkenes has been developed. The reaction proceeds through a radical pathway, with β-nitroalkenes serving as the vinylating reagents and the nitro group being cleaved in the process. Therefore, this method provides a viable synthetic approach to valuable secondary- and tertiary-alkylated styrene derivatives. Furthermore, control experiments were conducted and a plausible mechanism is proposed

Rh(III)-Catalyzed Selective Coupling of <i>N</i>‑Methoxy‑1<i>H</i>‑indole-1-carboxamides and Aryl Boronic Acids

A Rh­(III)-catalyzed selective coupling of <i>N</i>-methoxy-1<i>H</i>-indole-1-carboxamide and aryl boronic acids is reported. The coupling is mild and efficient toward diverse product formation, with selective C–C and C–C/C–N bond formation. Kinetic isotope effects studies were conducted to reveal a mechanism of C–H activation and electrophilic addition

Fe(III)-Catalyzed Hydroallylation of Unactivated Alkenes with Morita–Baylis–Hillman Adducts

An Fe­(III)-catalyzed hydroallylation of unactivated alkenes with Morita–Baylis–Hillman adducts via an Fe-catalyzed process is described. A variety of alkenes, including mono-, di-, and trisubstituted alkenes, could all smoothly convert to structural diversified cinnamates in this protocol. Interestingly, when the hydroxyl-containing alkenes were used, various lactones could be rapidly assembled. Moreover, this protocol could be applied to late-stage functionalization of natural products

Fe-Catalyzed Olefin Hydroamination with Diazo Compounds for Hydrazone Synthesis

A novel Fe-catalyzed olefin hydroamination with diazo compounds for accessing hydrazones has been developed. Diazo compounds are used as radical acceptors and can be trapped by the <i>in situ</i> generated alkyl radical toward C–N bond formation. The reaction conditions are mild, and the substrate scope is broad. Additionally, this hydroamination protocol is applicable for intramolecular reactions to construct diverse heterocycles

Rh(III)-Catalyzed C–H Activation/Cyclization of Indoles and Pyrroles: Divergent Synthesis of Heterocycles

We report herein a new strategy of the Rh­(III)-catalyzed C–H activation/cyclization of indoles and pyrroles, for the divergent synthesis of privileged heterocycles. A simple derivation of indoles and pyrroles to <i>N</i>-carboxamides with oxidative bidentate directing group could enable rhodacycle formation and late-stage redox-neutral cyclization with alkynes, alkenes and diazo compounds, for access to five- and six-membered fused heterocycles, such as pyrimido­[1,6-<i>a</i>]­indol-1­(2<i>H</i>)-one, 3,4-dihydropyrimido­[1,6-<i>a</i>]­indol-1­(2<i>H</i>)-one, and 1<i>H</i>-imidazo­[1,5-<i>a</i>]­indol-3­(2<i>H</i>)-ones. Kinetic isotope effect study was conducted, and a plausible mechanism was proposed. Furthermore, this protocol was applied to concise synthesis of 5-HT3 receptor antagonist in gram-scale

Concatenativeanalogical grammar: sample words (a), learning process (b), and correlation between learning and domain-general memory (c) are shown.

<p>Participants learned the two types of grammar in one language (/i/and/e/vowels triggered the application of the concatenative and analogical grammar, respectively) without any explicit instructions on how rules should be applied. The correlation between learning of these grammars and domain-general memory abilities provides further evidence of the underlying cognitive processes involved (c).</p

Performance on the Tower of London procedural memory test (TOL) (top) and language learning in the concatenative condition (proportion correct on untrained items) (bottom) by genotype groups (A2/A2 vs. A1).

<p>Error bars show standard error of the mean.</p

Relationship between Tone Perception and load of <i>ASPM-G</i> allele (left panel) and <i>MCPH1-C</i> allele (right panel).

<p>Significant genotype-phenotype correlation was found only in the <i>ASPM-G</i> allele.</p

A Hydrophobic Surface Is Essential To Inhibit the Aggregation of a Tau-Protein-Derived Hexapeptide

This paper seeks to understand how a macrocyclic β-sheet peptide inhibits the aggregation of the tau-protein-derived peptide Ac-VQIVYK-NH₂ (AcPHF6). Previous studies established that macrocyclic β-sheet peptide <b>1</b> inhibits AcPHF6 aggregation, while the sequence isomer in which the lysine and leucine residues at positions R₆ and R₇ are swapped has little effect on AcPHF6 aggregation. The current studies find that positions R₁, R₃, and R₇ are especially sensitive to mutations. Reducing hydrophobicity at these positions substantially diminishes inhibition. Although position R₅ is not sensitive to mutations that reduce hydrophobicity, it is sensitive to mutations that increase hydrophobicity. Enhanced hydrophobicity at this position substantially enhances inhibition. These studies establish that the hydrophobic surface comprising residues R₁, R₃, and R₇ is crucial to the inhibition process and that the residue R₅, which shares this surface, is also important. Collectively, these findings demonstrate that hydrophobic surfaces between β-sheet layers are important in inhibiting amyloid aggregation

Relationship between load of <i>ASPM</i>-G allele and neural tone suppression in temporal cortex.

<p>Top panel shows bilateral temporal (and left inferior frontal) activation when participants listened to linguistic tones (irrespective of relationship with genotype). Middle panel shows results from multiple regression analysis (conducted on the repeat condition). A negative relationship between load of <i>ASPM</i>-G allele and extent of fMRI adaptation to tone was found in the right primary and association auditory regions. For illustrative purposes (to depict the direction of the relationship), we extracted estimates from the significant clusters. As seen in the scatter plot (middle right panel), individuals with higher allele load showed more suppression (lower BOLD activity) when tones were repeated, indicative of more efficient neural processing to tone information. This relationship in the right temporal was present even when various cognitive factors (IQ, sound blending, auditory working memory scores) were added as covariates (bottom panel). The right temporal cortex (especially the right Heschl’s gyrus) has been shown in previous studies to be important for tone processing <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034243#pone.0034243-Bendor1" target="_blank">[35]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034243#pone.0034243-Warrier1" target="_blank">[37]</a>.</p