BODIPY dyes have attracted considerable attention as potential photosensitizers in dye‐sensitized solar cells (DSSCs) owing to their excellent optical properties and facile structural modification. This account focuses on recent advances in the molecular design of D‐π‐A BODIPY dyes for applications in DSSCs. Special attention has been paid to the structure‐property relationships of D‐π‐A BODIPY dyes for DSSCs. The developmental process in the modified position at the BODIPY core with a donor/acceptor is described. The devices based on 2,6‐modified BODIPY dyes exhibit better photovoltaic performance over other modified BODIPY dyes. Meanwhile, the research reveals the correlation of molecular structures (various donor chromophores, extended units, molecular frameworks, and long alkyl groups) with their photophysical and electrochemical properties and relates it to their performance in DSSCs. The structure‐property relationships give valuable information and guidelines for designing new D‐π‐A BODIPY dyes for DSSCs.
Asymmetric hydrogenation is one of the most efficient and atom‐economical tools to prepare chiral molecules. However, the enantiodiscrimination of simple, minimally functionalized olefins is still challenging and requires more sophisticated ligand design. Herein, we discuss our progress in the successful development of ligand design for the iridium‐catalyzed asymmetric hydrogenation of minimally functionalized olefins.
This article describes recent developments in C3‐symmetric tris‐urea low‐molecular‐weight gelators and their applications. The C3‐symmetric tris‐ureas are excellent frameworks to form supramolecular polymers through noncovalent interactions. In organic solvents, hydrophobic tris‐ureas form supramolecular gels. Amphiphilic tris‐ureas form supramolecular gels in aqueous media. Functional supramolecular gels were prepared by introducing appropriate functional groups into the outer sphere of tris‐ureas. Supramolecular hydrogels obtained from amphiphilic tris‐ureas were used in the electrophoresis of proteins. These electrophoreses results showed several unique characteristics compared to typical electrophoreses results obtained using polyacrylamide matrices.
Aggregation‐induced emission (AIE) luminogens show abnormal fluorescent behavior; they are non‐emissive in solution, but they become strongly emissive after aggregation. Sensing and imaging are the major applications of AIE luminogens. By properly manipulating the aggregation and deaggregation of AIE molecules, various bio‐/chemosensors have been developed. Moreover, AIE molecules with targeting groups have been devised for imaging of organelles and cancer cells. In this account, we report our recent work on the application of AIE luminogens for the construction of bio‐/chemosensors and imaging.
Multisubstituted olefins are fundamental motifs in organic compounds. In this account, we describe the synthesis of organic molecules bearing an olefinic moiety by the transition‐metal‐catalyzed regio‐ and stereoselective addition of a variety of interelement compounds to alkynes. Regio‐ and stereoselective silaboration, diborylation, and chlorothiolation have been achieved by using the transition‐metal catalysts. The subsequent cross‐coupling reactions of the boron‐containing alkenes to install various aryl groups afforded the corresponding tri‐ and tetraarylated olefins. This account describes our research on the highly regio‐ and stereoselective synthesis of multifunctionalized olefins such as tetraarylethenes with four different aryl groups.
We present herein a personal account of our achievements in the development of novel catalytic systems based on late‐transition‐metal complexes for the hydroarylation of alkynes. In particular, our targets were intermolecular hydroarylation reactions with arene or heteroarene substrates devoid of directing groups. We have shown that complexes of palladium, platinum or gold with N‐heterocyclic carbene (NHC) ligands can be particularly useful catalysts for this reaction; the NHC ligand imparts greater stability to the complex and renders the catalytic system more productive. Furthermore, we have identified promoters and reaction media that allow to significantly improve the catalytic activity under mild conditions, to control the reaction chemoselectivity and to steer it towards more complex products; thus making this reaction considerably more attractive for the synthetic chemist.
The direct functionalization of C(sp3)–H bonds is one of the most synthetically powerful research areas in current organic synthesis. Organocatalytic C(sp3)–H bond activation reactions have recently been developed in addition to the traditional metal‐catalyzed C(sp3)–H activation reactions. In this review, we aim to give a brief overview of organo‐ and organometallic internal redox cascade reactions with respect to the mechanism, the reactivity of hydrogen donors and acceptors, and the migration modes of hydrogen.
For efficient photoresponses of liquid‐crystal (LC) azobenzene (Az) polymer systems, planar LC orientation of the Az mesogenic group is required because the light irradiation process usually occurs with normal incidence to the film surface. However, LC molecules with a rodlike shape tend to orient perpendicularly to the film surface according to the excluded volume effect theory. This review introduces new approaches for inducing planar orientation in side‐chain LC Az polymer films via interface and surface molecular designs. The planar orientation offers efficient in‐plane photoalignment and photoswitching to hierarchical LC architectures from molecular LC mesogens and LC phases to mesoscopic microphase‐separated structures. These approaches are expected to provide new concepts and possibilities in new LC polymer devices.
With their remarkable properties and wide‐ranging applications, nanostructures of noble metals and metal oxides have been receiving significantly increased attention in recent years. The desire to combine the properties of these two functional materials for specific applications has naturally prompted research in the design and synthesis of novel nanocomposites, consisting of both noble metal and metal‐oxide components. In this review, particular attention is given to core–shell type metal oxide‐coated noble metal nanostructures (i.e., metal@oxide), which display potential utility in applications, including photothermal therapy, catalytic conversions, photocatalysis, molecular sensing, and photovoltaics. Emerging research directions and areas are envisioned at the end to solicit more attention and work in this regard.
Push–pull molecules represent a unique and fascinating class of organic π‐conjugated materials. Herein, we provide a summary of their recent extraordinary design inspired by letters of the alphabet, especially focusing on H‐, L‐, T‐, V‐, X‐, and Y‐shaped molecules. Representative structures from each class were presented and their fundamental properties and prospective applications were discussed. In particular, emphasis is given to molecules recently prepared in our laboratory with T‐, X‐, and Y‐shaped arrangements based on indan‐1,3‐dione, benzene, pyridine, pyrazine, imidazole, and triphenylamine. These push–pull molecules turned out to be very efficient charge‐transfer chromophores with tunable properties suitable for second‐order nonlinear optics, two‐photon absorption, reversible pH‐induced and photochromic switching, photocatalysis, and intercalation.
The feasibilities of Fujita's unit‐subduced‐cycle‐index (USCI) approach, Fujita's proligand method, and Fujita's stereoisogram approach have been demonstrated by applying them to cubane derivatives as probes. They provide us with a new set of theoretical foundations for comprehensive investigation of geometric and stereoisomeric features of stereochemistry. The new set of theoretical foundations is based on mathematical formulations so as to explore mathematical stereochemistry as a new interdisciplinary field of stereochemistry.
Supramolecular drug delivery systems (SDDSs), including various kinds of nanostructures that are assembled by reversible noncovalent interactions, have attracted considerable attention as ideal drug carriers owing to their fascinating ability to undergo dynamic switching of structure, morphology, and function in response to various external stimuli, which provides a flexible and robust platform for designing and developing functional and smart supramolecular nano‐drug carriers. Pillar[n]arenes represent a new generation of macrocyclic hosts, which have unique structures and excellent properties in host–guest chemistry. This account describes recent progress in our group to develop pillararene‐based stimuli‐responsive supramolecular nanostructures constructed by reversible host–guest interactions for controllable anticancer drug delivery. The potential applications of these supramolecular drug carriers in cancer treatment and the fundamental questions facing SDDSs are also discussed.
Coordination polymers serving as molecular magnetic refrigerants have been attracting great interest. In particular, coordination cluster compounds that demonstrate their apparent advantages on cryogenic magnetic refrigerants have attracted more attention in the last five years. Herein, we mainly focus on depicting aspects of syntheses, structures, and magnetothermal properties of coordination clusters that serve as magnetic refrigerants on account of the magnetocaloric effect. The documented molecular magnetic refrigerants are classified into two primary categories according to the types of metal centers, namely, homo‐ and heterometallic clusters. Every section is further divided into several subgroups based on the metal nuclearity and their dimensionalities, including discrete molecular clusters and those with extended structures constructed from molecular clusters. The objective is to present a rough overview of recent progress in coordination‐cluster‐based molecular magnetic refrigerants and provide a tutorial for researchers who are interested in the field.
As one of the most powerful and versatile methods for the construction of carbon–carbon bonds, the Suzuki–Miyaura cross‐coupling reaction has attracted great attention over the past three decades. In recent years, a huge amount of interest has been focused on the development of ligand‐free Suzuki–Miyaura reaction systems, which have the advantages of low cost, mild reaction conditions, and easy operation. So far, a number of ligand‐free Suzuki–Miyaura reaction systems have been developed by using simple palladium salts, nanopalladium, or supported palladium catalysts. In this account, we will review our recent research on the oxygen‐promoted ligand‐free Suzuki–Miyaura reaction. Interestingly, the oxygen‐promoting effect has been observed in different reaction media, including polyethylene glycol, organic/water mixed solvents and pure water. The oxygen‐promoted reaction systems demonstrate high efficiency for the construction of biaryls.
This review seeks to provide coverage on the recent advances in chiral squaramide‐catalyzed asymmetric transformations and their applications in the synthesis of a variety of chiral biologically active compounds. It aims to give an overview highlighting the new reaction types and enantioenriched medicinal scaffolds developed in the last few years.
A copper complex has proven to be a potent catalyst for forming a C–B bond via diborylation of arynes and alkynes, affording vic‐diborylarenes and vic‐diborylalkenes with high efficiency. A boryl‐substituted organocopper species, which is intermediately generated in the diborylation, has been found to be captured by a tin or a carbon electrophile, leading to three‐component borylstannylation or carboboration, in which C–B and C–Sn (or C) bonds are constructed simultaneously. Furthermore, reducing the Lewis acidity of the boron center with 1,8‐diaminonaphthalene decisively alters the regiochemical behavior of the borylcopper species, enabling the installation of a boryl moiety to occur at an internal carbon of terminal alkynes in borylstannylation and protoboration. Copper catalysis for C–Sn and C–Si bond‐forming processes via distannylation, hydrostannylation and silylstannylation, as well as silver catalysis for a C–B bond‐forming reaction, is also described.
The direct addition of Csp2–H bonds onto polar C=C, C=O, and C=N bonds is both synthetically and mechanistically important, because using aromatic C–H substrates in place of organometallic reagents provides a more direct and atom‐economical alternative to many important compounds without the pre‐generation of organometallic compounds from stoichiometric halides and the unavoidable generation of stoichiometric metal halide waste. In this account, we summarize our contributions to the transition‐metal‐catalyzed addition of aromatic C–H bonds to polar C=C, C=O, and C=N bonds via directing‐group‐assisted regiospecific reactions. These synthetic methods provide efficient access to benzylic alcohols, alkylbenzenes, 3‐substituted phthalides, N‐substituted phthalimides, N‐aryl benzamides, and indene derivatives from commercially available reagents. It is worth noting that valuable heterocycles such as 3‐substituted phthalides and N‐substituted phthalimides can be obtained in one step by this approach.
The potential applications of non‐proteinogenic amino acids have increased continuously since the introduction of these molecules into a ribosomal translation system. An increasing number of studies concerning topics, such as the addition of an artificial function to a protein, cellular expression of a protein with an artificial residue, and development of an artificial peptide with a novel function, have been done using these molecules. Here, we describe recent studies that elucidate the compatibility of non‐proteinogenic amino acids with ribosomal translation. We also describe the development of a simple and high‐speed selection method and its potential application for the creation of a novel functional peptide with non‐proteinogenic amino acids. As these studies have expanded the diversity of the artificial peptide library and increased the speed of novel functional peptide selection, they will significantly facilitate the development of new molecules, such as pharmaceutical drug candidates and bioassay probes.
This focus review summarizes our recent efforts on the synthetic applications of bithiophene dicarbanions generated from three bithiophene isomers: 2,2′‐, 3,3′‐, and 2,3′‐bithiophene. Based on these bithiophene dicarbanions, a series of dithienothiophenes ( DTT s) and cyclooctatetrathiophenes ( COTh s) were synthesized by intra‐ and intermolecular cyclizations, respectively. Moreover, recent applications of DTT and COTh in characteristic compounds such as dendrimers, thio[8]circulenes, double helicenes, and thienoacenes are summarized in this account. Besides the synthetic work, some photoelectric properties of the thiophene‐based oligomers including organic field‐effect transistors and organic photovoltaics are briefly reviewed.
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