Fen-Tair Luo

Palladium-catalyzed acylation of organozincs and other organometallics as a convenient route to ketones☆

Abstract The reaction of organozincs with acyl chlorides catalyzed by palladium-phosphine complexes, e.g., Pd(PPh 3 ) 4 , provides a highly general and convenient route to ketones.

Stereo- and regioselective routes to allylic silanes☆

Abstract The Ni- or Pd-catalyzed reaction of alkenyl iodides with Me 3 SiCH 2 Mgcl provides various types of allytrimethylsilanes in excellent yields in a highly stereo- and regioselective manner, while the Zr-catalyzed carboalumination of Me 3 SiCH 2 CCH followed by replacement of Al with carbon groups by known reactions produces allylsilanes represented by 2 .

pH-activatable near-infrared fluorescent probes for detection of lysosomal pH inside living cells

Four near-infrared fluorescent probes (A, B, C and D) have been synthesized, characterized, and evaluated for detection of lysosomal pH inside living cells. The fluorescent probes display highly sensitive and selective fluorescent response to acidic pH as the acidic pH results in drastic structural changes from spirocyclic (non-fluorescent) forms to ring-opening (fluorescent) forms of the fluorescent probes. The fluorescence intensities of the fluorescent probes (B, C and D) increase significantly by more than 200-fold from pH 7.4 to 4.2. The fluorescent probe D bearing the N-(2-hydroxyethyl) ethylene amide residue possesses the advantages of high sensitivity, excellent photostability, good cell membrane permeability, strong pH dependence, and low auto-fluorescence background. It has been successfully applied to selectively stain lysosomes and detect lysosomal pH changes inside normal endothelial and breast cancer cells.

Near-infrared fluorescent probes based on piperazine-functionalized BODIPY dyes for sensitive detection of lysosomal pH

Three acidotropic, near-infrared fluorescent probes based on piperazine-modified BODIPY dyes (A, B and C) have been developed for the sensitive and selective detection of lysosomal pH in living cells. Probes A and B display low solubilities in aqueous solutions, whereas probe C is highly water-soluble. The fluorescent responsive mechanism of these probes to lysosomal pH is based on intramolecular charge transfer (ICT) and potential photo-induced electron transfer from piperazine moieties at 3,5-positions to BODIPY cores in the near-infrared region. The sensitivity and selectivity of the probes to pH over metal ions have been investigated by spectroscopic analysis in aqueous solutions. The probes have low auto-fluorescence at physiological pH conditions, whereas their fluorescence intensities significantly increase when pH is shifted to an acidic condition. Furthermore, these three probes were successfully applied to the in vitro lysosome imaging inside normal endothelial and breast cancer cells.

Highly water-soluble BODIPY-based fluorescent probes for sensitive fluorescent sensing of zinc(II)

A zinc(ii) chelator bis(pyridin-2-ylmethyl)amine moiety has been incorporated into three different highly water-soluble dyes, 2-formyl-BODIPY, 2,6-diformyl BODIPY, and 2,6-diformyl-1,7-distyryl-BODIPY, at 2-position and 2,6-positions, resulting in three highly water-soluble BODIPY-based fluorescent probes A, B and C for zinc(ii) ions. Fluorescent probes A and B display sensitive fluorescent responses with significant fluorescence enhancement to zinc(ii) ions at pH 7.0 while fluorescent probe C shows two distinct measurable fluorescent signals at 521 nm and 661 nm, and displays ratiometric responses to zinc(ii) ions with fluorescence quenching at 661 nm and fluorescence enhancement at 521 nm. These three fluorescent probes exhibit excellent sensitive and selective responses to zinc(ii) ions. Intracellular zinc(ii) concentration could be monitored in cancer cells with fluorescent probe C.

BODIPY-based ratiometric fluorescent probes for the sensitive and selective sensing of cyanide ions

Three BODIPY-based ratiometric fluorescent probes (1, 2 and 3), with two being highly soluble in aqueous solution, were prepared by the condensation of 2-formyl-BODIPY dyes with 2,3,3-trimethyl-1-propyl-3H-indolium iodide and 2,3,3-trimethyl-1-(3-sulfonatepropyl)-3H-indolium for the selective and sensitive ratiometric fluorescent responses to cyanide ions.

Highly Water-Soluble BODIPY-Based Fluorescent Probe for Sensitive and Selective Detection of Nitric Oxide in Living Cells

A highly water-soluble BODIPY dye bearing electron-rich o-diaminophenyl groups at 2,6-positions was prepared as a highly sensitive and selective fluorescent probe for detection of nitric oxide (NO) in living cells. The fluorescent probe displays an extremely weak fluorescence with fluorescence quantum yield of 0.001 in 10 mM phosphate buffer (pH 7.0) in the absence of NO as two electron-rich o-diaminophenyl groups at 2,6-positions significantly quench the fluorescence of the BODIPY dye via photoinduced electron transfer mechanism. The presence of NO in cells enhances the dye fluorescence dramatically. The fluorescent probe demonstrates excellent water solubility, membrane permeability, and compatibility with living cells for sensitive detection of NO.

Efficient and high turnover homocoupling reaction of aryl iodide by the use of palladacycle catalyst. A convenient way to prepare poly-p-phenylene

Abstract Monoiodoarenes undergo reductive coupling to produce biaryls in high yields in the presence of less than 0.1 mol % of palladacyle and N , N -diisopropylethylamine in DMF at 100°C. Under similar reaction conditions, p -diiodobenzene produces poly- p -phenylene in greater than 85% isolated yields.

Controlled Knoevenagel reactions of methyl groups of 1,3,5,7-tetramethyl BODIPY dyes for unique BODIPY dyes

Formyl groups at 6- and 2,6-positions initiated Knoevenagel reactions of the methyl groups at the 7, and 1,7-positions of 1,3,5,7-tetramethyl BODIPY dyes with aromatic aldehydes. Formation of vinyl bonds at the 7-, and 1,7-positions facilitates further Knoevenagel reactions of the methyl groups at the 3,5-positions. This approach offers fast, facile and versatile ways to prepare potential novel building blocks of BODIPY dyes for conjugated oligomers, dendrimers, and highly water-soluble, near-infrared emissive sensing materials.

Intramolecular aminopalladation and cross coupling of acetylenic amines

Abstract Stereodefined 2-alkylidene-pyrrolidines and -piperidine were synthesized by treatment of an acetylenic amines with n-BuLi followed by addition of catalytic amount of Pd(OAc) 2 and PPh 3 in THF and 3 equiv of an organic halide.