A CuAAC/Ullmann C–C Coupling Tandem Reaction: Copper-Catalyzed Reactions of Organic Azides with <i>N</i>-(2-Iodoaryl)propiolamides or 2-Iodo-<i>N</i>-(prop-2-ynyl)benzenamines

A novel copper-catalyzed tandem reaction was developed by utilizing two famous copper-catalyzed reactions, CuAAC and Ullmann coupling. The trapping of the C–Cu intermediate produced in CuAAC led to further formation of an aryl C–C bond through intramolecular Ullmann C–C coupling

Pd-Catalyzed Desymmetric Intramolecular <i>O</i>‑Arylation Reaction: Enantioselective Synthesis of (3,4-Dihydro‑2<i>H</i>‑chromen-3-yl)methanols

An enantioselective intramolecular <i>O</i>-arylation was achieved through desymmetrization with Pd-catalyzed coupling reactions. The intramolecular asymmetric aryl C–O coupling reactions of 2-(2-haloaryl)propane-1,3-diols led to the enantioselective formation of chiral (3,4-dihydro-2<i>H</i>-chromen-3-yl)methanols in good yields and high enantiomeric selectivity

Synthesis of [1,2,3]Triazolo[1,5-<i>a</i>]quinoxalin-4(5<i>H</i>)-ones through Copper-Catalyzed Tandem Reactions of <i>N</i>-(2-Haloaryl)propiolamides with Sodium Azide

A simple and efficient approach for the synthesis of [1,2,3]triazolo[1,5-<i>a</i>]quinoxalin-4(5<i>H</i>)-ones is described. The methodology is based on a tandem reaction of 1-(2-haloaryl)propiolamides with sodium azide through a [3 + 2] azide–alkyne cycloaddition and intramolecular Ullmann-type C–N coupling process

Interaction between Cx43 and N-Cad proteins in human LA.

<p><b>A</b>. Representative double immunostaining image of Cx43 (green) and N-Cad (red). <b>B-E</b>. Enlarged images from a cropped area of image A including the Cx43/N-Cad overlay image (<b>B</b>), N-Cad (red; <b>C</b>), N-Cad pixel-by-pixel matched Cx43 signals (<b>D</b>), and non-N-Cad co-localized Cx43 (<b>E</b>). Arrows indicate stellate Cx43 pixels are in close proximity with the N-Cad pixel but do not pixel-by-pixel co-localize with N-Cad. <b>F</b>. Immunoblotting images of co-immunoprecipitated N-Cad protein with immunoprecipitated Cx43 proteins. Right column is the immunoprecipitated negative control without primary Cx43 antibody.</p

Confocal images of double immunofluorescence staining with Cx43 (green) and N-Cadherin (N-Cad; red) antibodies in rabbit left atrium (LA).

<p><b>A-C</b>. Representative confocal images of Cx43/N-Cad overlay (<b>A</b>), N-Cad (red; <b>B</b>) and Cx43 (green; <b>C</b>). <b>D-F</b>. Enlarged images from a cropped area of image A including the overlay image (<b>D</b>), N-Cad pixel-by-pixel matched Cx43 (<b>E</b>), and N-Cad non-pixel-by-pixel Cx43 (<b>F</b>). Arrows indicate stellate Cx43 pixels that are in close proximity with the N-Cad pixel but do not co-localize with N-Cad pixel-by-pixel. <b>G</b>. Representative histogram of quantified pixel intensity of Cx43 stained image. <b>H</b>. Representative plot for the mean intensity (blue curve) and standard deviation (red curve) of foreground pixels at different thresholds. <b>I</b>. Representative plot of J_T scores corresponding to R-value of four images from two young and two aged rabbit LA. <b>J</b>. Data plot of maximum J_T scores of the images from four young and four aged rabbit LA.</p

Determining an optimal radius of DNCU for Cx43_E-E and Cx43_S-S quantification. A-B & L-M.

<p>Representative Cx43 (green) and N-Cad (red) double immunostaining confocal images (<b>A, L</b>) and grayscale images (<b>B, M</b>) of enlarged single myocytes containing Cx43_E-E only (<b>A</b>) or both Cx43_E-E and Cx43_S-S (<b>L</b>). <b>C-J & N-U</b>. Grayscale images of the enlarged single myocytes with an incrementally increased DNCU radius (1, 5, 7, 30 IPD, respectively) for both N-Cad (left column) and Cx43 (right column). Arrows (<b>U</b>) indicate the inclusion of lateralized Cx43 by an extensively enlarged radius of the DNCU. <b>K & V</b>. Summarized data of quantitative Cx43 values corresponding to a continuously increased radii of DNCU when myocytes present Cx43_E-E only (<b>K</b>) or present both Cx43_E-E and Cx43_S-S (<b>V</b>). The Y-axis value of the first plateau reflects quantitative amount of ID located Cx43_E-E (red label) and the difference of the Y-axis value between the first and second plateaus indicates the amount of lateralized Cx43_S-S.</p

Schematic diagram of the blur algorithm with a dilated N-Cad unit (DNCU) radius of 1 inter-pixel distance (IPD) and 2 IPDs.

<p><b>A&a</b>. An N-Cad pixel at the center of a DNCU (<b>C&c</b>). Dilation radius equals to 1 IPD and 2 IPD (<b>B&b</b>). <b>D&d</b>. 3 overlapping adjacent DCNUs (R = 1 IPD & 2 IPDs, respectively) containing 3 adjacent N-Cad pixels. <b>E&e</b>. Three Cx43 pixels that are pixel-by-pixel matched with three N-Cad pixels, respectively. <b>F-G & f-g</b>. Two Cx43 pixels that do not co-localize with any N-Cad pixel-by-pixel but are included within the area of one of DCNU. All the DNCU covered Cx43 pixels (<b>E-G & e-g</b>) are defined as Cx43_E-E. <b>H&h</b>. Two Cx43 pixels that are located outside of all DCNU covered areas and are therefore categorized as Cx43_S-S.</p

Unidentified general data of the donors.

<p>F, Female; M, Male; CAU, Caucasian; AA, Africa American.</p

Comparing results of quantitative Cx43 distribution and abundance using layer-by-layer and maximum projection imaging quantification.

<p><b>A</b>. Representative sequential confocal images of Cx43 (green) and N-Cad (red) double immuno-stained young rabbit LA from focal layer 1 to layer 6. <b>B</b>. Histogram of quantified Cx43 immuno-stained signals from the maximum projection image. <b>C-D</b>. Summarized data of quantified Cx43_E-E and Cx43_S-S on young rabbit LA (n = 3; 53 images of each rabbit LA section) using layer-by-layer (<b>B</b>) and maximum projection (<b>C</b>) imaging quantification approaches. <b>D</b>. Pooled data of quantified Cx43_E-E and Cx43_S-S in young and aged rabbit LA using Layer-by-Layer imaging quantification from Z-stack confocal images (n = 4, 5; *p<0.001).</p

Using N-Cad as an internal housekeeping reference for imaging quantification.

<p><b>A-B</b>. Confocal images of Cx43 (green) and N-Cad (red) double immunostaining on two LA tissue sections obtained from two young rabbits (Rabbit-1 and Rabbit-2). <b>C</b>. Difference of quantitative total Cx43 raw data between the two confocal images obtained from Rabbit-1 and Rabbit-2 LA. <b>D</b>. A comparable amount of total Cx43 between the two rabbit LA samples when Cx43 raw data was normalized to N-Cad. <b>E</b>. Immunoblotting image of total Cx43 and GAPDH protein expression in Rabbit-1 and Rabbit-2 LA tissue homogenates. <b>F</b>. Comparison of quantitative immuno-stained Cx43 signal intensity with or without N-Cad normalization in aged rabbit LA.</p