Palladium-Catalyzed Direct C–H Allylation of Electron-Deficient Polyfluoroarenes with Alkynes

A palladium-catalyzed intermolecular direct C–H allylation of polyfluoroarenes with alkynes is reported. Unlike classic hydroarylation reactions, alkynes are used as allylic electrophile surrogates in this direct aromatic C–H allylation. As an atom-economic and efficient method, various linear allylated fluoroarenes were synthesized from two simple and easy-to-access feedstocks in good to excellent yields, as well as regio- and stereoselectivity

A DFT Study on Rh-Catalyzed Asymmetric Dearomatization of 2‑Naphthols Initiated with C–H Activation: A Refined Reaction Mechanism and Origins of Multiple Selectivity

Comprehensive DFT calculations have been performed to pursue deeper understandings on the mechanism of Rh-catalyzed asymmetric dearomatization of 2-naphthols initiated with C–H activation, which was developed by our group recently. A refined reaction mechanism is described here to account for the experimentally observed high enantio- and regioselectivity. Although the C–H activation was suggested to be involved in the turnover-limiting step, the enantioselectivity of the reaction was found to be determined during the migratory insertion of the alkyne. Different from the originally proposed mechanism, the final dearomatized product is afforded via a [1,3′]-reductive elimination directly from the eight-membered rhodacyclic intermediate generated from the migratory insertion step. In addition, the π–π interaction between the phenyl substituent on the alkyne and 2-naphthol might partially contribute to the high regioselectivity when unsymmetrical alkynes were employed as the substrates

Synthesis and Application of Chiral Spiro Cp Ligands in Rhodium-Catalyzed Asymmetric Oxidative Coupling of Biaryl Compounds with Alkenes

The vastly increasing application of chiral Cp ligands in asymmetric catalysis results in growing demand for novel chiral Cp ligands. Herein, we report a new class of chiral Cp ligands based on 1,1′-spirobiindane, a privileged scaffold for chiral ligands and catalysts. The corresponding Rh complexes are shown to be excellent catalysts in asymmetric oxidative coupling reactions, providing axially chiral biaryls in 19–97% yields with up to 98:2 er

Synthesis of Ferrocene-Based Pyridinones through Rh(III)-Catalyzed Direct C–H Functionalization Reaction

Synthesis of ferrocene-based pyridinones via Rh­(III)-catalyzed annulation of ferrocenecarboxamides with internal alkynes has been developed using a directing group as the internal oxidant. This method displays good functional group tolerance and delivers ferrocene-based pyridinones generally in moderate to good yields. Additionally, an asymmetric reaction can be achieved in the presence of a chiral catalyst <b>Rh1</b>

Diagnostic Performance of Echocardiography for the Detection of Acute Cardiac Allograft Rejection: A Systematic Review and Meta-Analysis

<div><p>Objective</p><p>Many studies have addressed the diagnostic performance of echocardiography to evaluate acute cardiac allograft rejection compared with endomyocardial biopsy. But the existence of heterogeneity limited its clinical application. Thus, we conducted a comprehensive, systematic literature review and meta-analysis for the purpose.</p><p>Methods</p><p>Studies prior to September 1, 2014 identified by Medline/PubMed, EMBASE and Cochrance were examined by two independent reviews. We conducted meta-analysis by using Meta-DiSc 1.4 software. An assessment tool of QUADAS-2 was applied to evaluate the risk of bias and applicability of the studies.</p><p>Results</p><p>Thirty studies met the inclusion criteria of meta-analysis. The four parameters of pressure half time, isovolumic relaxation time, index of myocardial performance and late diastolic mitral annular motion velocity were included in the meta-analysis, with a pooled diagnostic odds ratio of 10.43, 6.89, 15.95 and 5.68 respectively, and the area under the summary receiver operating characteristic curves value of 0.829, 0.599, 0.871 and 0.685 respectively.</p><p>Conclusion</p><p>The meta-analysis and systematic review demonstrate that no single parameter of echocardiography showed a reliable diagnostic performance for acute cardiac allograft rejection. A result of echocardiography for ACAR should be comprehensively considered by physicians in the context of clinical presentations and imaging feature.</p></div

Synthesis of Ferrocene-Based Pyridinones through Rh(III)-Catalyzed Direct C–H Functionalization Reaction

Synthesis of ferrocene-based pyridinones via Rh­(III)-catalyzed annulation of ferrocenecarboxamides with internal alkynes has been developed using a directing group as the internal oxidant. This method displays good functional group tolerance and delivers ferrocene-based pyridinones generally in moderate to good yields. Additionally, an asymmetric reaction can be achieved in the presence of a chiral catalyst <b>Rh1</b>

Summary receiver operator characteristic of pressure half time.

<p>The figure shows a symmetric curve with an area under the curve of 0.8292 and standard error of 0.1762. Each study is represented as a square in the summary receiver operating characteristic. The sample size is shown by the size of the square. AUC, area under the curve; SROC, Summary receiver operator characteristic; SE, standard error.</p

The summary of correlation between some major parameters and ACAR.

<p>A, late diastolic mitral inflow velocity; Am, Late diastolic mitral annular motion velocity; DT, deceleration time; E, early diastolic mitral inflow velocity; Em, early diastolic mitral annular motion velocity; IMP, index of myocardial performance; IVRT, isovolumic relaxation time; Sm, systolic mitral annular motion velocity; WT, ventricular wall thickness; +, the parameter correlates with rejection; −,the parameter does not correlate with rejection.</p><p>The summary of correlation between some major parameters and ACAR.</p

Summary receiver operator characteristic of isovolumic relaxation time.

<p>The figure shows a symmetric curve with an area under the curve of 0.5997 and standard error of 0.0392.</p

Pooled diagnostic odds ratio of index of myocardial performance for detecting acute cardiac allograft rejection.

<p>Effect sizes were pooled by random-effects models.</p