Synthesis of conjugated bisallenes by cooperative Cu/Pd-catalysed borylallenylation of 2-trifluoromethyl-1,3-enynes.

A cooperative Cu/Pd-catalysed borylallenylation of 2-trifluoromethyl-1,3-enynes with propargylic carbonates under mild reaction conditions was developed. This method provides facile and efficient access to conjugated bisallenes with a broad range of functional groups. Both aromatic and aliphatic 1,3-enynes can be utilized in this transformation to give the corresponding multi-substituted conjugated bisallenes.

Three-Component Borylallenylation of Alkynes: Access to Densely Boryl-Substituted Ene-allenes.

Ene-allenes serve as versatile building blocks in organic synthesis, and the development of their efficient preparation is valuable. Herein the synthesis of boryl-substituted ene-allenes utilizing a Cu/Pd-catalyzed borylallenylation of alkynes with propargylic carbonates and bis(pinacolato)diboron is reported. Densely (tetra-, penta-, and hexa-) substituted ene-allenes were synthesized in acceptable yield with high regio- and stereoselectivity. More important molecule structures can be obtained by subsequent modifications.

Diagnostic value of GLUT-1 in distinguishing malignant mesothelioma from reactive mesothelial cells: a meta-analysis.

Background: Previous studies have demonstrated the diagnostic value of glucose transporter 1 (GLUT-1) to distinguish malignant mesothelioma (MM) from reactive mesothelial cells (RMC), but the results are inconsistent. The purpose of this meta-analysis is to investigate the diagnostic accuracy of GLUT-1 in distinguishing MM from RMC.Methods: A systematical search was conducted until May 2019 in PubMed, Medline, Embase and the Cochrane Library. The revised tool for the quality assessment of diagnostic accuracy studies (QUADAS-2) was used to assess the quality of the eligible studies. The Stata15 and Review Manager5.3 software programmes were used to perform the meta-analysis.Results: A total of 24 studies, including 969 MM patients and 1080 RMC individuals were explored in the meta-analysis. The summary assessments revealed that the pooled sensitivity was 0.73 (95% CI, 0.62-0.81) and the pooled specificity was 0.95 (95% CI, 0.91-0.98). The area under the summary ROC curve (AUC) was 0.93 (95% CI: 0.91-0.95).Conclusions: GLUT-1 is highly accurate to distinguish MM from RMC.

Regioselective ß-Arylation of α-Angelica Lactone through Isomerization/Addition under Mild Conditions.

The conversion of biomass-based platform molecules into various high-value chemicals greatly promotes the utilization of renewable biomass resources. Herein, an example of Rh-catalyzed ß-arylation of levulinic-acid-derived α-angelica lactone was reported, providing the γ-lactone-structure products with high regioselectivity. Both arylboronic and alkenylboronic acids could be applied in this transformation. This reaction tolerated a variety of synthetically important functional groups. Moreover, the obtained γ-lactone products could be readily converted to high-value products such as 1,4-diols and γ-methoxy-carboxylates.

Rhodium(III)-Catalyzed Directed C-H Coupling with Methyl Trifluoroacrylate: Diverse Synthesis of Fluoroalkenes and Heterocycles.

An example of Rh-catalyzed C-H activation with methyl trifluoroacrylate for the synthesis of fluoroolefins and heterocycles (benzoindolizines) is reported. The types of products were determined by the directing group. The benzoindolizines and fluoroolefins were obtained by using pyridine and pyrazole as the directing group, correspondingly. These transformations present a number of advantages, such as oxidant-free reaction conditions and broad functional group tolerance. Moreover, this reaction greatly extends the application of fluoroolefins.

Copper-Catalyzed Alkynylboration of Alkenes with Diboron Reagents and Bromoalkynes.

An efficient method for the synthesis of homopropargylboronates by copper-catalyzed alkynylboration of alkenes with diboron reagents and bromoalkynes has been developed. The alkynylboration reaction features high selectivity and efficiency, mild reaction conditions, wide substrate scope, and functional-group compatibility, and is a highly attractive complement to existing methods for the synthesis of homopropargylboronates. Both the boryl and alkynyl groups are good potential functional groups for the subsequent manipulations that provide access to a variety of important molecule structures.