Double N,B-Type Bidentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C–H Borylation

Boryl ligands hold promise in catalysis due to their very high electron-donating property. In this communication double N,B-type boryl anions were designed as bidentate ligands to promote an sp² C–H borylation reaction. A symmetric pyridine-containing tetraamino­diborane(4) compound (<b>1</b>) was readily prepared as the ligand precursor that could be used, in combination with [Ir­(OMe)­(COD)]₂, to <i>in situ</i> generate a highly active catalyst for a broad range of (hetero)­arene substrates including highly electron-rich and/or sterically hindered ones. This work provides the first example of a bidentate boryl ligand in supporting homogeneous organometallic catalysis

Eight 3D lines (in pink color) on two orthogonal planes used in the simulations, where the small pyramids stand for camera viewpoints.

<p>Eight 3D lines (in pink color) on two orthogonal planes used in the simulations, where the small pyramids stand for camera viewpoints.</p

Experimental results.

<p>(a) Calibration cube; (b) planar checkerboard; (c) model house; (d) corridor.</p

Distances between the edges on the unit cube by the three metrics.

<p>Distances between the edges on the unit cube by the three metrics.</p

Linear algorithm: LINa.

<p>Linear algorithm: LINa.</p

Stability of the algorithms with respect to different noise levels.

<p>(a) 3D errors; (b) algebraic errors; (c) orthogonal errors.</p

NAC blocked the rotenone-induced microglial activation.

<p>(A) BV2 cells treated with 1 µM rotenone for 24 hours or 1 µg/mL LPS for 24 hours or co-treated with 5 mM NAC and either 1 µM rotenone for 24 hours or 1 µg/mL LPS for 24 hours. The TNFα levels in the culture media of the treated BV2 cells were measured by ELISA. (B) BV2 cells were treated with as indicated in (A). Then, the cells were lysed, and the lysates were immunoblotted with the indicated antibodies. The activated IL-1β cleaved by caspase-1 is indicated as cleaved IL-1β.</p

NAC blocked activation of the rotenone-induced NF-κB signaling pathway.

<p>(A) BV2 cells treated with 1 µM rotenone for 6 hours or 1 µg/mL LPS for 1 hour or co-treated with 5 mM NAC and either 1 µM rotenone for 6 hours or 1 µg/mL LPS for 1 hour. The cells were immunoblotted with anti-IκB antibodies. Tubulin served as the loading control. (B) BV2 cells treated with 1 µM rotenone for 6 hours or 1 µg/mL LPS for 1 hour or co-treated with 5 mM NAC and either 1 µM rotenone for 6 hours or 1 µg/mL LPS for 1 hour. The cells were fixed and labeled with DAPI (blue) and anti-p65 antibodies (red). The scale bar represents 10 µm. (C) The cytoplasmic and nuclear fractions from the BV2 cells that were treated as indicated in (B) were subjected to immunoblot analysis with anti-p65 antibodies. GAPDH served as the marker for the cytoplasmic fraction, and Max served as the marker for the nuclear fraction.</p

Rotenone directly activated the NF-κB signaling pathway in BV2 cells.

<p>(A) Various doses of rotenone or LPS were administered to BV2 cells as indicated for 6 hours or 1 hour, respectively. The cell lysates were immunoblotted with anti-pIKK or anti-IKK antibodies. GAPDH served as the loading control. (B) BV2 cells were treated as described in (A). The cell lysates were immunoblotted with anti-IκB antibodies. (C) Quantitative analysis of the data from (B), showing the density of IκB relative to that of the loading control (GAPDH). The data are presented as the mean ± S.E.M. n = 3, *p<0.05, one-way ANOVA. (D) BV2 cells were treated with rotenone for 6 hours or LPS for 1 hour. The cells were fixed and labeled with DAPI (blue) or anti-p65 antibodies (red). The scale bar represents 10 µm. (E) The cytoplasmic and nuclear fractions from the treated BV2 cells were immunoblotted with anti-p65, anti-GAPDH or anti-Max antibodies. (F) Quantitative analysis of the data from (E), showing the density of nuclear p65 relative to that of the loading control (Max). The data are presented as the mean ± S.E.M. n = 3, *p<0.05, **p<0.01, one-way ANOVA.</p

Stability of different algorithms with respect to geometrical configurations.

<p>(a) 3D errors; (b) Algebraic errors; (c) orthogonal errors.</p