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An unprecedented strategy has been developed involving the earth-abundant Cu-catalyzed hydrocarboxylation of alkynes with HCOOH to (E)-acrylic derivatives with high regio- and stereoselectivity via synergistic effects with ppm levels of a Pd catalyst. Both symmetrical and unsymmetrical alkynes bearing various functional groups were successfully hydrocarboxylated with HCOOH, and the modification of a pharmaceutical molecule exemplified the practicability of this process. This protocol employs HCOOH as both a CO surrogate and hydrogen donor with 100% atom economy and it can be viewed as an alternative approach for indirect CO2 utilization. Mechanistic investigations indicate a Cu/ppm Pd cooperative catalysis mechanism via alkenylcopper species as potential intermediates formed from Cu-hydride active catalytic species with HCOOH as a hydrogen source. This bimetallic system involving inexpensive Cu and trace Pd provides a reliable and efficient hydrocarboxylation method to access industrially useful acrylic derivatives with HCOOH as a hydrogen source, and it provides novel clues for optimizing other Cu–H-related co-catalytic systems. [ABSTRACT FROM AUTHOR]

An unprecedented strategy has been developed involving the earth-abundant Cu-catalyzed hydrocarboxylation of alkynes with HCOOH to (E)-acrylic derivatives with high regio- and stereoselectivity via synergistic effects with ppm levels of a Pd catalyst. Both symmetrical and unsymmetrical alkynes bearing various functional groups were successfully hydrocarboxylated with HCOOH, and the modification of a pharmaceutical molecule exemplified the practicability of this process. This protocol employs HCOOH as both a CO surrogate and hydrogen donor with 100% atom economy and it can be viewed as an alternative approach for indirect CO2 utilization. Mechanistic investigations indicate a Cu/ppm Pd cooperative catalysis mechanism via alkenylcopper species as potential intermediates formed from Cu-hydride active catalytic species with HCOOH as a hydrogen source. This bimetallic system involving inexpensive Cu and trace Pd provides a reliable and efficient hydrocarboxylation method to access industrially useful acrylic derivatives with HCOOH as a hydrogen source, and it provides novel clues for optimizing other Cu–H-related co-catalytic systems. [ABSTRACT FROM AUTHOR]

Developing an efficient and easy‐to‐handle strategy in designing catalysts for CO2 reduction into CO by harnessing sunlight is a promising project. Here, a facile strategy was developed to design a Re catalyst modified with an ionic secondary coordination sphere for photoreduction of CO2 to CO by visible light. By adding ionic liquids or tuning a different ionic secondary coordination sphere, it was discovered that an outstanding optical property, other than CO2 absorption ability or the ability to dissociation of chloride anion, is the prerequisite for catalyst design. Accordingly, a novel Re catalyst, {Re[BpyMe(tris(2‐hydroxyethyl)amine)](CO)3Cl}Br (Re‐THEA), was designed, screened, and resulted in a relative high quantum yield (up to 34 %) for visible‐light‐induced CO2 reduction with a single‐molecule system. DFT calculations, combined with experimental outcomes, suggested the pendant ionic tris(2‐hydroxyethyl)amino (THEA) group on Re‐THEA can enhance visible‐light absorption, stabilize reaction intermediates, and suppress the Re–Re dimer formation. [ABSTRACT FROM AUTHOR]

The reaction of propargylic amines and CO2 can provide high‐value‐added chemical products. However, most of catalysts in such reactions employ noble metals to obtain high yield, and it is important to seek eco‐friendly noble‐metal‐free MOFs catalysts. Here, a giant and lantern‐like [Zn116] nanocage in zinc‐tetrazole 3D framework [Zn22(Trz)8(OH)12(H2O)9⋅8 H2O]n Trz=(C4N12O)4− (1) was obtained and structurally characterized. It consists of six [Zn14O21] clusters and eight [Zn4O4] clusters. To our knowledge, this is the highest‐nuclearity nanocages constructed by Zn‐clusters as building blocks to date. Importantly, catalytic investigations reveal that 1 can efficiently catalyze the cycloaddition of propargylic amines with CO2, exclusively affording various 2‐oxazolidinones under mild conditions. It is the first eco‐friendly noble‐metal‐free MOFs catalyst for the cyclization of propargylic amines with CO2. DFT calculations uncover that ZnII ions can efficiently activate both C≡C bonds of propargylic amines and CO2 by coordination interaction. NMR and FTIR spectroscopy further prove that Zn‐clusters play an important role in activating C≡C bonds of propargylic amines. Furthermore, the electronic properties of related reactants, intermediates and products can help to understand the basic reaction mechanism and crucial role of catalyst 1. [ABSTRACT FROM AUTHOR]

Cupric subcarbonate (Cu2(OH)2CO3) was found to be effective for the reductive functionalization of CO2 to produce formamides and methylamines with phenylsilane as reductant. Interestingly, N-formylation and N-methylation were switched on/off by subtly choosing the ligand: DPPB (1,4-bis(diphenylphosphino)butane) promoted N-methylation whereas Ph2CyP (diphenylcyclohexylphosphine) favored for N-formylation. [ABSTRACT FROM AUTHOR]

The reaction of propargylic amines and CO 2 can provide high-value-added chemical products. However, most of catalysts in such reactions employ noble metals to obtain high yield, and it is important to seek eco-friendly noble-metal-free MOFs catalysts. Here, a giant and lantern-like [Zn 116 ] nanocage in zinc-tetrazole 3D framework [Zn 22 (Trz) 8 (OH) 12 (H 2 O) 9 ⋅8 H 2 O] n Trz=(C 4 N 12 O) 4- (1) was obtained and structurally characterized. It consists of six [Zn 14 O 21 ] clusters and eight [Zn 4 O 4 ] clusters. To our knowledge, this is the highest-nuclearity nanocages constructed by Zn-clusters as building blocks to date. Importantly, catalytic investigations reveal that 1 can efficiently catalyze the cycloaddition of propargylic amines with CO 2 , exclusively affording various 2-oxazolidinones under mild conditions. It is the first eco-friendly noble-metal-free MOFs catalyst for the cyclization of propargylic amines with CO 2 . DFT calculations uncover that Zn II ions can efficiently activate both C≡C bonds of propargylic amines and CO 2 by coordination interaction. NMR and FTIR spectroscopy further prove that Zn-clusters play an important role in activating C≡C bonds of propargylic amines. Furthermore, the electronic properties of related reactants, intermediates and products can help to understand the basic reaction mechanism and crucial role of catalyst 1., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Doping non-metals onto TiO 2 has been regarded as a promising way to gain a more effective photocatalyst. In this paper, N, F-codoped TiO 2 was synthesized by the sol-gel method, demonstrating both high adsorption capacity and high photocatalytic activity under visible light irradiation. Samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and UV-visible diffuse reflectance spectra (UV-vis DRS). The results show that N, F-codoping can reduce the impact of calcination temperature on the structure and morphology of the sample, resulting in the sample exhibiting good thermal stability, even when the calcination temperature changes in a large range, instead of rutile, the anatase around 20 nm is the only phase in N, F-codoped samples. It can be clearly observed from the SEM images that N, F-codoped samples calcined at different temperatures are in the state of scattered particles with small size and good dispersed property. And it is vivid that the absorption intensity of N, F-codoped TiO 2 samples in the visible light range increases substantially in DRS. According to the result of photocatalytic activity experiment, N, F-codoped TiO 2 samples calcined at 973 K exhibited the highest degradation rate for Methylene Blue.

Objective: To investigate magnetic resonance imaging (MRI) characteristics of ovarian carcinosarcoma and the diagnostic value of MRI., Methods: The MRI features of ovarian carcinosarcoma and clinical data of 5 patients with ovarian carcinosarcoma were reviewed. All the lesions were confirmed by surgery and pathological examination., Results: MRI of ovarian carcinosarcoma in the 5 cases all showed large tumor mass and heterogeneous high-intensity on T2-weighted images and low-intensity on T1-weighted images, with laminar or stripe-like enhancement. Hemorrhage and necrosis were also displayed in some lesions. In two cases, the tumors invaded the greater omentum, sigmoid colon and the body of the uterus, with regional lymph node involvement. Pelvic effusion was observed in all the cases with pelvic hematocele in 1 case., Conclusion: MRI is useful in the detection and staging of ovarian carcinosarcoma.