Palladium-catalyzed difluorocarbene transfer enables access to enantioenriched chiral spirooxindoles.

We disclose herein an unprecedented Pd-catalyzed difluorocarbene transfer reaction, which assembles a series of structurally interesting chiral spiro ketones with generally over 90% ee. Commercially available BrCFCOK serves as the difluorocarbene precursor, which is harnessed as a user-friendly and safe carbonyl source in this transformation. Preliminary mechanistic studies exclude the formation of free CO in the reaction process, and importantly, we also find that BrCFCOK outcompete gaseous CO and several common CO surrogates in this asymmetric process.

Catalytic Asymmetric Cascade Dearomatization of Indoles via a Photoinduced Pd-Catalyzed 1,2-Bisfunctionalization of Butadienes.

Photoinduced Pd-catalyzed bisfunctionalization of butadienes with a readily available organic halide and a nucleophile represents an emerging and attractive method to assemble versatile alkenes bearing various functional groups at the allylic position. However, enantiocontrol and/or diastereocontrol in the C-C or C-X bond-formation step have not been solved due to the open-shell process. Herein, we present a cascade asymmetric dearomatization reaction of indoles via photoexcited Pd-catalyzed 1,2-biscarbonfunctionalization of 1,3-butadienes, wherein asymmetric control on both the nucleophile and electrophile part is achieved for the first time in photoinduced bisfunctionalization of butadienes.

Regioselective Synthetic Approach to Higher Alkenes from Lower Alkenes with Sulfoxides in the Fe/HO System Direct Alkylation or Arylation of the Csp-H Bond on the C═C Bond of Alkenes.

The regioselective synthetic approach to higher alkenes from lower alkenes by using sulfoxides as alkyl or aryl reagents in the Fe/HO system has been developed. This reaction realized direct alkylation or arylation of alkenes. In this reaction, sulfoxides afforded one Csp or Csp atom to the C═C bond of alkenes; one new Csp-Csp bond or Csp-Csp bond was formed.

[3+1+1+1] Annulation to the Pyridine Structure in Quinoline Molecules Based on DMSO as a Nonadjacent Dual-Methine Synthon: Simple Synthesis of 3-Arylquinolines from Arylaldehydes, Arylamines, and DMSO.

A [3+1+1+1] annulation of arylamines, arylaldehydes, and dimethyl sulfoxide (DMSO) to the pyridine structure in quinolines using DMSO as a nonadjacent dual-methine (═CH-) synthon is disclosed. In this annulation, arylamines provide two carbon atoms and one nitrogen atom, arylaldehydes furnish one carbon atom, and DMSO provides two nonadjacent methines (═CH-) to the pyridine ring in quinoline molecules. This annulation provides a simple approach for the synthesis of 3-arylquinolines from readily available substrates in useful yields.

Unexpected Annulation between 2-Aminobenzyl Alcohols and Benzaldehydes in the Presence of DMSO: Regioselective Synthesis of Substituted Quinolines.

An unexpected annulation among 2-aminobenzyl alcohols, benzaldehydes, and DMSO to quinolines has been disclosed. For the reported annulation between 2-aminobenzyl alcohols and benzaldehydes, the change of the solvent from toluene to DMSO led to the change of the product from the diheteroatomic cyclic benzoxazines to monoheteroatomic cyclic quinolines. This annulation can be used to synthesize regioselectively different substituted quinolines by the choice of different 2-amino alcohols, aldehydes, and sulfoxides as substrates.

Two C═C Bond Participation in Annulation to Pyridines Based on DMF as the Nonadjacent N and C Atom Donors.

Two C═C bond participation in annulation to pyridines using ,-dimethylformamide (DMF) as the N1 and C4 synthons has been carried out. In this reaction, DMF contributed one N atom and one C atom to two disconnected positions of pyridine ring, with no need for an additional nitrogen source. Two C═C bonds in two molecules of substituted styrenes offered four carbon atoms in the presence of iodine and persulfate.

Metal-Free-Catalyzed Synthesis of Allyl Nitriles via C-C Coupling between Olefins and Azobis (Alkyl-carbonitrile).

The metal-free-catalyzed synthesis of allyl nitriles from C-C coupling between olefins and azobis was carried out. Key on this work was that the synthesis of allyl nitriles directly using olefin as a starting material was considered to be more efficient and economical than the alkyne, alkynyl carboxylic acid, or cinnamic acid used in previous works. Moreover, in this reaction, iodine served as the sole promoter, azobis served as a cyanation reagent, and N was the only nontoxic byproduct that could avoid the utilization of metal catalysts and virulent nitrile reagents and generation of toxic wastes.

Uniform Cerium-Based Coordination Polymer Microsnheres: Preoaration and Upconversion Emission.

Homogeneously doped Yb3+ and Er3+ cerium-based coordination polymer (CP) microspheres have been successfully synthesized on a large scale through a simple solvothermal route with 2,5-pyridinedicarboxylic acid (2,5-H2PDC) as the organic linker. CeO2: Yb3+, Er3+ porous microspheres were obtained by annealing the corresponding CP microspheres at 600 °C for 4 h under atmospheric pressure. These as-prepared products were characterized by Powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersion X-ray (EDX) spectroscopy, Thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis.

Hybrid Membrane of Agarose and Lanthanide Coordination Polymer: a Selective and Sensitive Fe(3+) Sensor.

A new hybrid membrane was prepared by a facile method based on a highly luminescent lanthanide coordination polymer and agarose. The soft membrane was characterized by FT-IR, PXRD, SEM and luminescence. It is found that the soft membrane is a highly selective and sensitive sensor, among 19 metal ion solutions of Fe(3+), Mg(2+), Li(+), Ca(2+), Zn(2+), Cu(2+), Ba(2+), Mn(2+), Ru(3+), Cr(3+), Ag(+), Sr(2+), Cd(2+), Na(+), Ni(2+), Pb(2+), Fe(2+), Hg(2+) and Ca(2+), only Fe(3+) quench the luminescence.