In recent years, transition-metal-catalyzed C-H functionalization has gradually developed into a powerful tool for the synthesis of ferrocenes in an atom- and step-economic fashion. However, despite significant achievements, the vast majority of these C-H functionalizations required precious 4d or 5d transition metal catalysts. The use of inexpensive and sustainable 3d metals in the C-H functionalization of ferrocenes remains challenging, especially the development of asymmetric versions.
View Article and Find Full Text PDFWe report here strategic functionalization of the FDA approved chelator deferasirox (1) in an effort to produce organelle-targeting iron chelators with enhanced activity against A549 lung cancer cells. Derivative 8 was found to have improved antiproliferative activity relative to 1. Fluorescent cell imaging revealed that compound 8 preferentially localises within the lysosome.
View Article and Find Full Text PDFCp*Cobalt(III)-catalyzed enantioselective C-H amidation of ferrocenes using monoprotected amino acids (MPAAs) as chiral ligands was developed. The reaction was performed under mild conditions in high yields (up to 97%) with moderate enantioselectivity (up to 77.5:22.
View Article and Find Full Text PDFThe amide-directed cobalt(III)-catalyzed C-H amidation of ferrocene carboxamides using 1,4,2-dioxazol-5-ones as robust and efficient amidating reagents has been developed. This reaction proceeds efficiently under mild reaction conditions with good functional group tolerance, providing expedient access to a broad range of ferrocenes containing a nitrogen group on the Cp ring.
View Article and Find Full Text PDFDibenzocyclooctadiene lignans are an interesting class of molecules because of their unique structure based on an axially chiral biaryl moiety as well as their significant biological activity. Herein, we describe the development of a palladium-catalyzed atroposelective C-H alkynylation and its application in gram-scale, stereocontrolled formal syntheses of (+)-isoschizandrin and (+)-steganone. tert-Leucine was identified as an efficient, catalytic transient chiral auxiliary.
View Article and Find Full Text PDFThe Ru-catalyzed meta-C-H benzylation of arenes bearing pyridyl, pyrimidyl, and pyrazolyl directing groups with toluene derivatives has been reported. Heptafluoroisopropyl iodide (CFI) was employed as both a mild oxidant and radical initiator. This reaction showed excellent site-selectivity and tolerated a wide range of functional groups, providing a new strategy for the synthesis of various diarylmethane moieties.
View Article and Find Full Text PDFPurpose: Cdx2 is an essential transcription factor in intestinal epithelial cell differentiation and proliferation. However, to our knowledge the expression and role of Cdx2 in the development of intestinal cystitis glandularis, a metaplastic lesion induced by chronic inflammation, remained to be explored.
Materials And Methods: Real-time polymerase chain reaction was used to examine Cdx2, LI-cadherin and villin expression in typical and intestinal cystitis glandularis, and normal bladder tissue.