9 research outputs found

    Rhodium-Catalyzed β‑Selective Oxidative Heck-Type Coupling of Vinyl Acetate via C–H Activation

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    An efficient Rh­(III)-catalyzed direct <i>ortho</i>-C–H olefination of acetanilides with vinyl acetate was developed. This protocol provides a straightforward pathway to a series of (<i>E</i>)-2-acetamidostyryl acetates, giving access to indole derivatives following a simple hydrolysis/cyclization process

    Dual Effects of Cyclopentadienyl Ligands on Rh(III)-Catalyzed Dehydrogenative Arylation of Electron-Rich Alkenes

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    Despite extensive research on transition metal-catalyzed Fujiwara–Moritani type C–H olefinations, the alkenes used in these transformations are still mainly limited to active acrylate esters and styrenes. Selective aryl C–H olefination with electron-rich alkenes is recognized as a challenging issue. We herein report that simple and readily accessible electron-deficient [CpRh­(III)] and [Cp<sup>CF<sub>3</sub></sup>Rh­(III)] (Cp<sup>CF<sub>3</sub></sup> = C<sub>5</sub>Me<sub>4</sub>CF<sub>3</sub>) complexes are powerful catalysts for dehydrogenative arylation of electron-rich alkenes, including vinyl acetates, enamides, and vinyl ethers. Employing an electron-withdrawing Cp or Cp<sup>CF<sub>3</sub></sup> ligand instead of the privileged Cp* (C<sub>5</sub>Me<sub>5</sub>) ligand not only can facilitate the electrophilic aryl C–H rhodation but also can lower the olefin insertion barrier. Both electron-withdrawing and electron-donating directing groups such as -CONR<sub>2</sub> and -NHAc could be employed in these reactions, which provides convenient routes toward a series styryl acetates, <i>N</i>-acetylindoles, and aryl methyl ketones

    Long-Term Outcomes of Radio-Frequency Catheter Ablation on Ventricular Tachycardias Due to Arrhythmogenic Right Ventricular Cardiomyopathy: A Single Center Experience

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    <div><p>Aims</p><p>To summarize our experience of radiofrequency catheter ablation (RFCA) for recurrent drug-refractory ventricular tachycardias (VTs) due to arrhythmogenic right ventricular cardiomyopathy (ARVC) in our center over the past 11 years and its related factors.</p><p>Methods and Results</p><p>We reviewed 48 adults (mean age 39.9 ± 12.9 years, range: 14 to 65) who met the present ARVC diagnostic criteria and accepted RFCA for VTs from December 2004 to April 2016. The patients received a total of 70 procedures using two ablation approaches, the endocardial approach in 52 RFCAs, and the combined epicardial and endocardial approach (the combined approach) in 18 RFCAs. Kaplan-Meier survival analysis showed that the combined approach achieved better acute procedural success (<i>p</i> = 0.003) and better long-term outcomes (<i>p</i> = 0.028) than the endocardial approach. Patients who obtained acute procedural success with non-inducibility had better long-term outcomes (<i>p</i> < 0.001). COX regression of multivariate analysis showed that procedural success was the only factor that benefited long-term outcome, irrespective of the endocardial or the combined approach (<i>p</i> = 0.001). The rate of sudden cardiac death (SCD) in patients without procedural success was significantly higher than that in patients with procedural success (<i>p</i> = 0.005). All patients without implantable cardioverter defibrillator (ICD) implantation who had successful final RFCA survived.</p><p>Conclusions</p><p>The combined approach resulted in better procedural success and long-term VT-free survival compared with the endocardial approach in ARVC patients with recurrent VTs. Acute procedural success with non-inducibility was strongly related to better long-term VT-free survival and reduced SCD, irrespective of whether this was achieved by the endocardial approach or the combined approach.</p></div

    This series of pictures show the electrophysiological characteristics in the RV epicardium of an ARVC patient.

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    <p>(A) A concealed entrainment within the isthmus of the reentrant circuit. The post-pacing interval (PPI) was 320 ms, almost equal to the VT cycle length (326 ms). The interval between the stimulation signal to onset of QRS complex (S-QRS) was 108 ms (108/320 = 0.34), indicating that the location was within the center of the isthmus. (B) The sequential activation of fractionated potentials. (C) VT stopped during ablation. (D) The three-dimensional activation map (Ensite Navx Velocity) of this patient’s RV epicardium which shows a reentry in the RV free wall. (E) Fluorescence of the mapping catheters. DD: St Jude Medical DuoDeca catheter.</p

    The substrate maps of the RV endocardium and epicardium of an ARVC patient (CARTO3 system).

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    <p>(A) The fractionated potentials are marked as blue dots within a low voltage zone and ablation energy was delivered within the low voltage zone with fractionated potentials in the RV endocardium. (B) This is the substrate map of the RV epicardium and ablation marks within the low voltage zone with fractionated potentials of the same patient.</p
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