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.
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.
Electron‐deficient enamines such as enaminones and enaminoesters are moieties showing widespread application in organic synthesis. Among the various available electron‐deficient enamines, the N,N‐disubstituted amino‐functionalized ones (tertiary enamines) represent a class of special enamines with distinct properties and important applications. Based on our longstanding interest in exploring novel synthetic methods using electron‐deficient tertiary enamines, we present herein the research advances in organic synthesis via domino reactions making use of the combinatorial C–N, C=C, C–H, and other bond transformations of electron‐deficient tertiary enamines.
Transition‐metal complex triplet photosensitizers are versatile compounds that have been widely used in photocatalysis, photovoltaics, photodynamic therapy (PDT) and triplet–triplet annihilation (TTA) upconversion. The principal photophysical processes in these applications are the intermolecular energy transfer or electron transfer. One of the major challenges facing these triplet photosensitizers is the short triplet‐state lifetime, which is detrimental to the above‐mentioned photophysical processes. In order to address this challenge, transition‐metal complexes showing long‐lived triplet excited states are highly desired. This review article summarizes the development of this fascinating area, including the molecular design rationales, the principal photophysical properties, and the applications of these complexes in PDT and TTA upconversion.
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.
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.
Our journey in organophosphorus research over the past 26 years is compiled in this Personal Account. Advances in palladacycle design have engendered a shift in our focus from template‐mediated transformations to catalysis for the direct preparation of chiral phosphines containing a wide variety of functional groups. Novel approaches to access previously inaccessible phosphines and their applications in cancer research are summarized herein.
Rhodamine hydrazides and hydroxamates derived from hydrazines and hydroxylamines have been applied as fluorescent chemosensors. Reaction‐based irreversible probes based on the specific chemical reactions of reactive target species have been developed and applied in bio‐imaging studies. The strong chelation frames provided by the rhodamine hydrazides and hydroxamates have been utilized for the monitoring of metal ions, amino acids, and reactive acid derivatives. This Personal Account focuses on our perspective of developing fluorescent probes based on rhodamine hydrazides and hydroxamates.
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.
This article draws, with a simplified but rigorous approach, the typical procedure for the design and optimization of functional multicomponent structures for light to chemical energy conversion for two series of multipartite structures based on prototypical chromophores: polypyridyl metal complexes and porphyrinoids. Starting from a photophysical study performed by steady‐state and time‐resolved spectroscopic methods, the full deactivation dynamics of the light‐absorbing chromophore(s) are disclosed. The preferred deactivation step (electron transfer in this case) is then optimized. This can be done by simply operating on the solvent, but also by changing structure/components that can alter electronic and nuclear factors, via continuous feedback with the research groups in charge of the synthesis. With a presentation suitable for a wide audience, it is here discussed how the effective design of functional multicomponent structures for charge separation can be achieved.
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.
Sulfonyl indoles, as well as related azolyl derivatives, have been recently introduced in synthesis as stable precursors of reactive indolenine intermediates. This personal account reports on the discovery of sulfonyl azoles and their practical utilization in many synthetic processes for the preparation of functionalized 3‐substituted indoles, indazoles, and pyrroles. The indolenine intermediates obtained by treatment of sulfonyl azoles with Brønsted bases or Lewis acids can be considered as vinylogous imino derivatives that can be made to react with different nucleophilic reagents. These include organometallic reagents, reducing agents, stabilized carbanions, and heteronucleophiles. The controlled and mild conditions for the generation of indolenines from sulfonyl azoles make these substrates particularly useful in asymmetric synthesis, exploiting organo‐ or metal‐catalyzed processes. Although less exploited, sulfonyl indoles can also be involved in photochemical processes for the preparation of polycyclic derivatives.
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.
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.
Acenes, a type of polycyclic aromatic hydrocarbon containing linearly fused benzene rings, have received much attention from organic chemists, physical chemists, and materials scientists, due to their intriguing properties and potential applications in organic electronics. Without doubt, acene chemistry has been one of the hottest topics among the π‐conjugated systems. However, poor stability of acenes is the prominent issue that limits their applications. In this personal account, we summarize different strategies developed in our group to construct and stabilize acenes and acene analogues. In addition, the unique properties and applications of some molecules will be discussed.
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.
Concise and efficient methods for the synthesis of enantiomers of fire ant venom alkaloids solenopsin and isosolenopsin A, B, and C are described. These syntheses are based on diastereoselective electrophilic substitution of enatiomerically‐pure α‐lithiated 2‐alkylpiperidine. 相似文献
Reaction between α‐halo‐nicotinic esters and a nucleophilic source such as the N‐methylpyrrolidin‐2‐one (NMP) gave unexpected results. The presence of the halide on the pyridine gave a very interesting migration reaction. Extension to 6‐methylnicotinic ester derivatives lead to an unexpected carbanion condensation. 相似文献
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