A convenient and efficient alpha-allylation of N-aryl tetrahydroisoquinolines has been achieved. This transformation can be realized under only visible light irradiation without the aid of transition metals or photocatalysts. The mechanism involves a novel in situ-generated electron-donor-acceptor (EDA) complex between the N-aryl tetrahydroisoquinolines and an allyl or a benzyl bromide. Irradiation with purple light triggered single-electron transfer (SET) from the N-aryl tetrahydroisoquinolines to the allyl or benzyl bromide of the EDA complex, inducing the formation of the corresponding allyl or benzyl radical and the subsequent radical-radical coupling. This approach represents the first example of a photocatalyst- and transition-metal-free alpha-allylic and benzylic functionalization of N-aryl tetrahydroisoquinolines.

A convenient and efficient α-allylation of N-aryl tetrahydroisoquinolines has been achieved. This transformation can be realized under only visible light irradiation without the aid of transition metals or photocatalysts. The mechanism involves a novel in situ-generated electron-donor-acceptor (EDA) complex between the N-aryl tetrahydroisoquinolines and an allyl or a benzyl bromide. Irradiation with purple light triggered single-electron transfer (SET) from the N-aryl tetrahydroisoquinolines to the allyl or benzyl bromide of the EDA complex, inducing the formation of the corresponding allyl or benzyl radical and the subsequent radical-radical coupling. This approach represents the first example of a photocatalyst- and transition-metal-free α-allylic and benzylic functionalization of N-aryl tetrahydroisoquinolines. This journal is © The Royal Society of Chemistry.

Cotton fiber is an abundant natural material, which has a long history of application in human daily life. However, a report on using such material in catalysis for organic synthesis is rare. We envisaged that the hydroxyl groups on the surface of cotton fiber could be utilized for functionalization and further immobilization of organic catalysts. In this report, we demonstrate the facile functionalization of cotton fiber by growing polymer brushes on its surface and further anchoring of Rose Bengal (RB) organic photocatalyst. This novel composite cotton photocatalyst demonstrated high efficiency in catalyzing cross-dehydrogenative coupling reactions and N-demethylation reactions with irradiation of visible light. The catalytic reaction can be facilely scaled up by a homemade circulating flow reactor.

The successfully developed polydimethylsiloxane (PDMS, a stable hydrophobic polymer material) sponge supported DMAP can be used as base catalyst and ligand to facilitate a series of organic transformations with high efficiency and good reusability in water. This PDMS sponge DMAP can provide much better catalytic activities and selectivities than free DMAP in water. Through an easy-to-build continuous flow reactor, the PDMS sponge DMAP facilitated reactions can be facilely scaled up. This porous hydrophobic PDMS sponge material will be a promising carrier for the development of highly efficient recyclable catalysts in water. (C) 2018 Elsevier Inc. All rights reserved.

Polydimethylsiloxane (PDMS, a stable hydrophobic polymer material) sponge-supported nanometer-sized gold can be used as a highly efficient recyclable catalyst for cross-dehydrogenative coupling of tertiary amines with various nucleophiles in water. This PDMS sponge nanometer gold catalyst can provide much better activity than the free nanometer gold in water. The reaction can be scaled up by using an easy-to-build continuous flow reactor. These results indicate the potential application of porous hydrophobic PDMS sponge material as a promising support for highly efficient recyclable catalysts in water. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

As an emerging type of optically active material, semiconductor nanocrystals (NCs) stabilized by chiral molecules have attracted much attention. Owing to the wide range of potential applications of chiral perovskite NCs, the development of these materials is of great importance, but there has been a lack of relevant studies. Here, we describe an investigation of the properties of chiral perovskite NCs obtained using post-synthetic ligand exchange (achiral ligand/chiral ligand). These are found to exhibit mirror-image circular dichroism spectra. It is the chirality of the ligand (enantiomeric 1,2-diaminocyclohexane, DACH) that is most likely responsible for the induction of chiroptical activity in these NCs. Furthermore, their chiroptical properties and the corresponding mechanisms are found to depend strongly on the amount of capping ligand. When excess DACH is used to cap the surface of the NCs, their chiroptical properties are induced mainly by aggregation of DACH on the surface in a chiral pattern. In contrast, when small amounts of DACH are used for the capping, it is mainly surface distortion (or defects) and electronic interaction mechanisms that contribute to the chiroptical behavior of the NCs. In both cases, the anisotropy factors of the NCs are of the order of 10-3, which is comparable to or larger than the values reported for other chiral semiconductor and metal NCs. This work opens the door toward further understanding of chiroptical perovskite NCs and their potential applications. © 2017 Author(s).

Circular dichroism (CD) and circular polarized luminescence (CPL) are useful for various applications. However, it is difficult to achieve excellent CD and CPL in differently polar solvents simultaneously. This work provides a simple but efficient way to construct violet-blue fluorescent and water-soluble chromophore through the construction of rigid conformation of the alkyne architecture. By introducing proline pendants into alkyne architecture, the chromophore exhibits reasonable CD and CPL properties in the lowly and highly polar solvents. More importantly, even in water, the chromophore displays effective CD anisotropy factor (g(abs) similar to 1 x 10(-3)) and luminescence dissymmetry factor (g(lum) similar to 2 x 10(-3)), as well as high fluorescence quantum yield (Phi up to 35%). Additionally, the chromophore exhibits large two-photon CD according to the theoretically calculated results. The excellent chiroptical properties from the simple organic fluorophore enables its future applications in miniatured optoelectronic devices and CPL-based bioimaging.

[GRAPHICS]A series of pyrano[ 2,3-d] pyrimidine derivatives have been synthesized by the reaction of 2-amino-3cyano- 4H-pyrans and acetic anhydride with acid catalyst. This method is very efficient because of short reaction times and easy work- up, and it provides an efficient and promising synthetic strategy for the construction of the tetracyclic pyrano[ 2,3-d] pyrimidine skeleton. The X-ray crystal structures of products are confirmed, and the possible mechanism is provided in this paper.

Herein we propose a hybridization chain reaction based kinetics competition strategy able to recognize the combination/sequence of input signals. Further, a DNA priority encoder and a keypad lock were constructed. This strategy allowed us to develop a one-pot assay that can automatically and smartly respond to multiple inputs.