New synthesis of multi-layer 3D chiral molecules has been developed under novel conditions to give better outcomes. The aggregation-induced emission (AIE), UV irradiation/excitation, charge transfer ...(CT) and local excited (LE) ππ* transitions have been investigated on a representative individual enantiomer of
pseudo C
2
asymmetry which was made possibly by differentiating moieties on phosphorous on N-phosphonyl ring of chiral sandwich framework. Meanwhile, a new tandem C-N/C-C coupling reaction was unexpectedly rendered providing a novel access to special benzoacarbazoles.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The first asymmetric catalytic approach to multilayer 3D chirality has been achieved by using Suzuki‐Miyaura cross‐couplings. New chiral catalysts were designed and screened under various catalytic ...systems that proved chiral amide‐phosphines to be more efficient ligands than other candidates. The multilayer 3D framework was unambiguously determined by X‐ray structural analysis showing a parallel pattern of three layers consisting of top, middle and bottom aromatic rings. The X‐ray structure of a catalyst complex, dichloride complex of Pd‐phosphine amide, was obtained revealing an interesting asymmetric environment nearby the Pd metal center. Three rings of multilayer 3D products can be readily changed by varying aromatic ring‐anchored starting materials. The resulting multilayer products displayed strong luminescence under UV irradiation and strong aggregation‐induced emission (AIE). In the future, this work would benefit not only the field of asymmetric synthesis but also materials science, in particular polarized organic electronics, optoelectronics and photovoltaics.
The first asymmetric catalytic approach to multilayer 3D chirality by using Suzuki‐Miyaura cross‐couplings in the presence of new chiral amide‐phosphines is reported. The resulting multilayer products showed strong luminescence under UV irradiation, and displayed strong aggregation‐induced emission (AIE).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A new strategy has been established for the synthesis of functionalized chromene and chroman derivatives via a Cs2CO3-catalyzed domino addition of 2′-hydroxychalcone derivatives with allenoates, ...which can serve as a general avenue for the construction of multireplaced chromene derivatives. Chemoselectivity of this synthesis was found to depend on substituents on substrates. Good to excellent yields were achieved under simple and mild conditions at room temperature.
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IJS, KILJ, NUK, PNG, UL, UM
In this work, we present a strategy for the preparation of functionalized 2,3-dihydrobenzofuran derivatives
the Cs
CO
-catalyzed domino annulation of enantiopure chiral salicyl
-phosphonyl imines ...with bromo malonates, which offers an avenue for the construction of 2,3-dihydrobenzofurans. Nineteen examples were synthesized in impressive chemical yields and diastereoselectivity. The products were purified simply by washing the crude mixtures with hexanes following group-assisted purification chemistry/technology to bypass traditional separation methods which often result in a loss of product. The absolute configuration was unambiguously assigned by X-ray structural analysis.
In this work, we present a strategy for the preparation of functionalized 4
-chromene derivatives
a Cs
CO
-catalyzed 4 + 2 cycloaddition of enantiopure chiral salicyl
-phosphonyl imines with ...allenoates. Fifteen examples were achieved in excellent yields and diastereoselectivity. The products were purified simply by washing the crude mixture with hexanes following the Group-Assisted Purification (GAP) chemistry/technology to bypass traditional separation methods. The absolute configuration was unambiguously determined by X-ray structure analysis.
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IJS, KILJ, NUK, UL, UM, UPUK
Invited for the cover of this issue is Guigen Li and co-workers at Texas Tech University and Nanjing University. The cover artwork shows that chirality phenomena exists in the universe and in nature, ...including at micro and molecular levels. Read the full text of the article at 10.1002/chem.202100700.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Unprecedented chiral multilayer folding 3D polymers have been assembled and regulated by uniform and differentiated aromatic chromophore units between naphthyl piers. Screening catalysts, catalytic ...systems and monomers were proven to be crucial for asymmetric catalytic Suzuki–Miyaura polycouplings for this assembly. X‐ray crystallography of the corresponding dimers and trimers revealed the absolute configuration and the intermolecular packing pattern. Up to 61 960 Mw/41 900 Mn and m/z 4317 for polymers and oligomers, as confirmed by gel permeation chromatography (GPC) and MALDI‐TOF MS, indicated that these frameworks were composed of multiple stacked layers. The resulting multiple π‐assemblies exhibited remarkable optical properties in aggregated states (photoluminescence in solids and aggregation‐induced emission in solutions), as well as reversible redox properties in electrochemical performance.
A first asymmetric catalytic approach to multilayer 3D folding polymers by using Suzuki–Miyaura cross‐coupling in the presence of chiral catalysts. The resulting multiple π‐assemblies exhibited remarkable optical properties in aggregated states (photoluminescence in solids and aggregation‐induced emission in solutions), as well as reversible redox properties in electrochemical performance.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Chirality has existed in nature from the early stages of life on Earth. A new form of chirality, multilayer 3D chirality, has been established involving nearly parallel patterns. This work presents ...the first asymmetric catalytic approach to multi‐layer 3D chirality. New complexes of Pd and chiral amide‐phosphine ligands were utilized as catalysts for Suzuki‐Miyaura coupling for assembling various multilayer 3D chiral molecules, which displayed strong luminescence under UV irradiation and strong aggregation‐induced emission (AIE) of different colors. More information can be found in the Full Paper by G. Li et al. (DOI: 10.1002/chem.202100700).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
In this work, we present a strategy for the preparation of functionalized 4H-chromene derivatives via a Cs2CO3-catalyzed 4 + 2 cycloaddition of enantiopure chiral salicyl N-phosphonyl imines with ...allenoates. Fifteen examples were achieved in excellent yields and diastereoselectivity. The products were purified simply by washing the crude mixture with hexanes following the Group-Assisted Purification (GAP) chemistry/technology to bypass traditional separation methods. The absolute configuration was unambiguously determined by X-ray structure analysis.
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IJS, KILJ, NUK, UL, UM, UPUK
In this study, polystyrene was functionalized with Meldrum's acid toward the introduction of the ketenes (CCO) system to its backbone for producing a dramatically reactive intermediate. Meldrum's ...acid, as a ketene source, was reacted by poly(styrene‐co‐p‐chloromethyl styrene) through a simple nucleophilic reaction to synthesize poly(styrene‐co‐styryl Meldrum's acid). Then, the pendant Meldrum's acid under thermal treatment converted to ketene intermediate resulting in highly reactive polystyrenes derivatives, which rapidly reacted by nucleophilic reagents to afford ultimate organic building blocks. The polystyrene derivatives were characterized using elemental analysis, FT‐IR, high‐resolution solid‐state NMR, thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTG). To clarify the evolutionary mechanisms of polystyrene products, density functional theory (DFT) method B3LYP with the 6–311++G(2d,p) basis set was used. We studied the preparation of polystyrene model compounds through Meldrum's acid thermolysis and nucleophilic substitution. The kinetic and thermodynamic parameters in all reactions and the structural and electronic properties of all molecules were calculated. These data exhibited that based on Gibbs Free energy values, the structure of syndiotactic polystyrene is more stable than that of isotactic polystyrene. Furthermore, it was found that the presence of an electron donor or acceptor substituent on the polystyrene structure affects the electronic bandgap.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
![Asymmetric [4 + 2] cycloadd...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/2046-2069/small "Asymmetric [4 + 2] cycloaddition synthesis of 4 H -chromene derivatives facilitated by group-assisted-purification (GAP) chemistry")
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