Pd-Catalyzed Enantioselective Hydroamidocarbonylation of α-Substituted Acrylamides to Chiral Succinimides.

With the aid of an innate amide group, an intramolecular Pd-catalyzed enantioselective hydroamidocarbonylation reaction of α-substituted acrylamides was developed, and a series of chiral 2-substituted succinimides were obtained in moderate to high yields and enantioselectivities. The generality of this approach was demonstrated by the carbonylation of both aryl- and alkyl-substituted acrylamides containing numerous functional groups.

Diastereoselective Alkene Hydroesterification Enabling the Synthesis of Chiral Fused Bicyclic Lactones.

Palladium-catalysed diastereoselective hydroesterification of alkenes assisted by the coordinative hydroxyl group in the substrate afforded a variety of chiral γ-butyrolactones bearing two stereocenters. Employing the carbonylation-lactonization products as the key intermediates, the route from the alkenes with single chiral center to chiral THF-fused bicyclic γ-lactones containing three stereocenters was developed.

Access to α-Cyano Carbonyls Bearing a Quaternary Carbon Center by Reductive Cyanation.

Reductive cyanation of tertiary alkyl bromides using electrophilic cyanating reagent and zinc reductant was developed, providing various α-cyano ketones, esters, and carboxamides containing a nitrile-bearing all-carbon quaternary center in good to excellent yields under mild reaction conditions. The corresponding reaction mechanism involving in situ generated organozinc reagent and reactivity distinction was elucidated by density functional theory computation.

A colorimetric and fluorescent chemosensor based on diarylethene for simultaneous detection and discrimination of biothiols.

In this work, a novel probe D-HBT-NBD (1O) based on diarylethene to detect biothiols (including Cys, Hcy and GSH) was synthesized and the relative colorimetric and fluorescent properties were tested. The probe exhibited excellent photochromic properties and showed apparent colorimetric and fluorescent signals for Cys, Hcy and GSH. The probe can selectively detect Cys, Hcy and GSH by naked eyes for its open-ring isomer 1O and can discriminate Cys from Hcy/GSH by apparent color change from light orange to dark pink at the closed-ring state under the irradiation of UV light. At the excitation wavelength of 465 nm, the probe could be used to discriminate GSH from Cys/Hcy with no fluorescent emission at 570 nm. Taking advantage of the photochromic property of the diarylethene moiety and the different fluorescent properties of NBD derivatives of GSH and Cys/Hcy, 1O could be used as a novel probe to discriminate Cys, Hcy and GSH from each other simultaneously. Meanwhile, a logic gate was constructed based on the colorimetric and fluorescent properties of 1O.

An efficient and sensitive chemosensor based on salicylhydrazide for naked-eye and fluorescent detection of Zn2.

We reported here the synthesis of a diarylethene with a 2,4-dihydroxybenzoyl hydrazine moiety (1O) for Zn2+ recognition. The compound is easy to prepare with a high yield up to 85%. Compound 1O can act as a highly selective and specific fluorescent sensor for Zn2+ without interference by other common metal ions. The LOD for Zn2+ detection was determined to be 1.28 × 10-6 mol L-1. Meanwhile, 1O can be used as a naked-eye detector for the Zn2+ ion with an obvious color change from colorless to olive. Based on the fluorescent properties of 1O, we constructed a logic circuit with four inputs of the combinational stimuli of UV/vis light and Zn2+/EDTA, and one output of fluorescence intensity.