Novel Spiro-Configured PET Chromophores Incorporating 4,5-Diazafluorene Moiety as an Electron Acceptor

Remote steric control for undirected meta-selective C-H activation of arenes

Regioselective functionalization of arenes remains a challenging problem in organic synthesis. Steric interactions are often used to block sites adjacent to a given substituent, but they do not distinguish the remaining remote sites. We report a strategy based on remote steric control, whereby a roof-like ligand protects the distant para site in addition to the ortho sites, and thereby enables selective activation of meta carbon-hydrogen (C-H) bonds in the absence of ortho or para substituents. We demonstrate this concept for iridium-catalyzed meta-selective borylation of various monosubstituted arenes, including complex drug molecules. This strategy has the potential to expand the toolbox of C-H bond functionalization to previously nondifferentiable reaction sites.

A Sc(OTf)3 catalyzed dehydrogenative reaction of electron-rich (hetero)aryl nucleophiles with 9-aryl-fluoren-9-ols

New pyrenyl substituted 9,9-diarylfluorene with nonplanar conformations, high fluorescence quantum yield and excellent thermal and morphological stability was synthesized by our current protocol.

Ruthenium(ii) complexes incorporating carbazole–diazafluorene based bipolar ligands for dye sensitized solar cell applications

A new type of ruthenium sensitizers, S3 and S4, consisting of carbazole–diazafluorene based bipolar ancillary ligands have been synthesized and characterized for dye sensitized solar cells.

Carbon Cationic Relay via Superelectrophiles: Synthesis of Spiro-diazafluorenes

Superelectrophilic-initiated carbon cationic relay reactions of diazafluorenones with phenols were developed to provide strategically novel and atom-economic access to spirodiazafluorenes via tandem Friedel-Crafts reaction, nucleophilic addition, and intramolecular cyclization sequences. A range of spirodiazafluorenes that are difficult to synthesize with traditional protocols has been constructed successfully in middle to high yields using this method.

Enantioselective fluorescent sensors for chiral carboxylates based on BINOL — Synthesis and chiral recognition

The four novel derivatives of 1,1′-bi-2-naphthol (BINOL) have been prepared, and the structures of these compounds have been characterized by IR, MS, 1H and 13C NMR spectroscopy, and elemental analysis. The enantioselective recognition of these receptors has been studied by fluorescence titration and 1H NMR spectroscopy. The receptors exhibited different chiral-recognition abilities towards some enantiomers of chiral materials and formed 1:1 complexes between host and guest. The receptors exhibit excellent enantioselective fluorescent-recognition ability towards the amino acid derivatives.