The classical Sonogashira reaction of aryl electrophiles in the presence of Pd catalysts has been well established as a potent method for arylalkyne synthesis. However, the site-selective C(sp)-C(sp) cross-coupling strategy using a non-noble-metal catalyst is rare. An efficient alternative approach for the synthesis of arylalkynes via a Cu-catalyzed Sonogashira-type reaction promoted by visible light is described.
View Article and Find Full Text PDFAs the new H-cluster models, six diiron propanedithiolate (PDT) complexes with mono- and diphosphine ligands have been prepared and structurally characterized. The monophosphine model complex (mu-PDT)Fe(2)(CO)(5)[Ph(2)PNH(t-Bu)] (1) was prepared by reaction of parent complex (mu-PDT)Fe(2)(CO)(6) (A) with 1 equiv of Ph(2)PNH(t-Bu) in refluxing xylene, whereas A reacted with 1 equiv of Me(3)NO.2H(2)O in MeCN at room temperature followed by 1 equiv of Ph(2)PH to give the corresponding monophosphine model complex (mu-PDT)Fe(2)(CO)(5)(Ph(2)PH) (2).
View Article and Find Full Text PDFInsulin-induced gene 2 (Insig2) was recently identified as a putative positive prognostic biomarker for colon cancer prognosis. Insig2 has been previously reported to be an endoplasmic reticulum (ER) membrane protein, and a negative regulator of cholesterol synthesis. Here we report that Insig2 was validated as a gene with univariate negative prognostic capacity to discriminate human colon cancer survivorship.
View Article and Find Full Text PDFNew C-functionalized propanedithiolate-type model complexes (1-8) have been synthesized by functional transformation reactions of the known complex [(mu-SCH2)2CH(OH)]Fe2(CO)6 (A). Treatment of A with the acylating agents PhC(O)Cl, 4-pyridinecarboxylic acid chloride, 2-furancarbonyl chloride, and 2-thiophenecarbonyl chloride in the presence of Et3N affords the expected C-functionalized complexes [(mu-SCH2)2CHO2CPh]Fe2(CO)6 (1), [(mu-SCH2)2CHO2CC5H4N-4]Fe2(CO)6 (2), [(mu-SCH2)2CHO2CC4H3O-2]Fe2(CO)6 (3), and [(mu-SCH2)2CHO2CC4H3S-2]Fe2(CO)6 (4). However, when A is treated with the phosphatizing agents Ph2PCl, PCl3 and PBr3, both C- and Fe-functionalized complexes [(mu-SCH2) 2CHOPPh2-eta1]Fe2(CO)5 (5), [(mu-SCH2) 2CHOPCl2-eta1]Fe2(CO)5 (6), and [(mu-SCH2) 2CHOPBr2-eta1]Fe2(CO)5 (7) are unexpectedly obtained via intramolecular CO substitution by P atoms of the initially formed phosphite complexes.
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