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The direct conversion of specific C−H bonds to C−Si bonds in alkanes or aromatics via catalytic methods has attracted growing research interest. Herein, we report the preparation of a new iridium catalyst supported on a naphthyridine‐based porous organic polymer and its successful application in the dehydrogenative silylation of 2‐arylphenols or alcohol and hydrosilanes to access ring‐fused oxasilacycles. The synthetic method exhibits broad substrate scope and good functional group compatibility while avoiding the use of hydrogen acceptors. In addition, this organic polymer supported iridium catalyst could be easily recovered from the reaction system and reused for at least seven times without apparent deactivation. This research provides new insights for the further design of heterogeneous nanocatalysts and contributes to the synthesis of silicon‐substituted functional molecules. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developing a new palladium-catalyzed nitroarene/nitrile reductive cross-annulation chemistry that facilitates straightforward access to pyrrolo[1,2-a]quinoxaline derivatives. • A range of nitriles are activated as carbon synthons to form intramolecular C N and C C bonds. • The use of environment-friendly water and inexpensive HCOONa/HCOOH as the solvent and hydrogen donors, respectively. • The catalyst is conveniently recycled by filtration and can be reused at least five times without obvious deactivation. Green palladium-catalyzed nitroarene/nitrile reductive cross-annulation chemistry that facilitates straightforward access to pyrrolo[1,2-a]quinoxaline derivatives is described herein. A range of nitriles are activated as carbon synthons to form intramolecular C N and C C bonds using this chemistry. The synthetic protocol has the advantages of broad substrate scope, excellent functional group tolerance, and the use of environment-friendly water and inexpensive HCOONa/HCOOH as the solvent and hydrogen donors, respectively. The catalyst is conveniently recycled by filtration and can be reused at least five times without obvious deactivation. This study offers an important platform for converting bulk chemical motifs into value-added functional frameworks. [ABSTRACT FROM AUTHOR]

Objectives: Objectives Pseudohypoparathyroidism type 1A (PHP1A) is caused by maternal inheritance of GNAS mutations. It is characterized by the resistance to several hormones, primarily the parathyroid hormone (PTH), and the features of Albright's hereditary osteodystrophy. Case presentation: Here, we present a family comprised two affected brothers with PHP1A and identify a novel mutation (c.277C>T) in the GNAS gene. The siblings developed a slightly different presentation in the same clinical condition. Although both patients presented with PTH resistance, which is the hallmark of PHP, the proband showed the thyroid-stimulating hormone resistance with the progression of heterotopic ossification from skin and subcutaneous tissue into deep connective tissue, while the younger brother with normocalcemia did not show the resistance to other hormones. The patients may inherit the mutation from their mother who presumably carries the mutation as a mosaicism. Conclusions: Our case highlights the significance of considering mosaicism as an explanation for apparent de novo cases of pseudohypoparathyroidism. [ABSTRACT FROM AUTHOR]

Selective C-H annulation with alkynes is one of the most useful tools to synthesize heterocycles. Herein, we developed novel porous organic polymers supported ruthenium (POPs-Ru) as highly efficient catalysts for cascade aromatization of quinoxalin-2(1 H )-one and C-H annulation with alkynes. Both terminal and internal alkynes were successfully transferred to furo[2,3 -b ]quinoxaline derivatives with good functional group tolerance and high regioselectivity by using POPs-Ru catalysts. Furthermore, the catalyst exhibited high activity and could be reused at least five times without obvious deactivation of this coupling reaction. This study offers an important platform for the immobilization of molecular metal catalysts for C-H functionalization.

The replacement of fossil resources with biomass resources in the construction of N-heterocycles is rapidly attracting research interest. Herein, we report palladium-catalyzed selective hydrogenative coupling of nitroarenes and phenols based on a transfer hydrogenation strategy, allowing straightforward access to spirocyclic pyrrolo- and indolo-fused quinoxalines, a class of compounds found in numerous natural alkaloids. The synthetic protocol is characterized by a broad substrate scope and the utilization of biomass-derived reactants and commercially available catalysts. In such transformations, high-pressure and explosive hydrogen are not required. This report provides a new protocol for converting biomass-derived phenols into value-added nitrogen-containing chemicals.

Previous studies have reported inconsistent results regarding the association between homocysteine (Hcy) levels and calcific aortic valve disease (CAVD). We investigate the association between Hcy levels in patients with CAVD and controls by conducting a systematic review and meta-analysis. We conducted a systematic search of studies published prior to the end of March 2017 in the PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials and the Chinese Biomedical Literature databases. Eligible studies evaluating plasma Hcy levels in CAVD patients and controls were identified by two independent investigators. Standardized mean difference (SMD) and the corresponding 95% confidence intervals (95% CIs) were estimated using the random-effects model. Ten studies involving 6349 participants were included. Pooled analysis demonstrated that Hcy levels were significantly elevated in patients with CAVD compared with controls (pooled SMD: 0.57, 95% CI: 0.36-0.79). This elevation was more obvious in American and Asian populations than in Turkish populations. Furthermore, Hcy levels were significantly elevated in patients with mild-to-moderate CAVD and severe CAVD. Our results demonstrate that CAVD is associated with elevated Hcy levels., Competing Interests: CONFLICTS OF INTEREST No conflicts of interest to disclose.