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Synthesis of Donor-Acceptorπ-Conjugated Macrocycles by Post-Functionalization

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Chinese Journal of chemistry 2021年第10期39卷 2705-2710页

作者： Junting Wang Qingyun Wan Junzhi Liu department of chemistry and state key laboratory of synthetic chemistry The University of Hong KongPokfulam RoadHong KongChina

Main observation and conclusion In this paper,two novel donor-acceptor(D-A)macrocyclic compounds 5 and 7 were successfully synthesized by post-functionalization of a planar dimer macrocycle(1)and a highly twisted trimer macrocycle(2),respectively,via controllable oxidation of methoxy groups and condensation between diketones and phenylenediamine in succession.Compared with unembellished 9,10-dimethoxyphenanthrene,the resultant dibenzo[a,c]phenazine motif is electron-deficient rather than electron-rich,yielding two D-Aπ-conjugated macrocycles with more contractive energy gaps.Density functional theory(DFT)calculations further support the unequivocal evidence of the D-A properties of macrocycles 5 and 7.The difference of their photophysical properties was investigated by the aid of ultraviolet-visible absorption and fluorescence spectrophotometers.Furthermore,the stacking patterns of 7 and its contrastπ-conjugated macrocycle trimer(2)were compared via the analysis of X-ray single crystal,in which the electron-deficient dibenzo[a,c]phenazine unit provides extra interaction sites,resulting in orderly arrangement of 7 in the solid state.

关键词： Macrocycles Post-functionalization Donor-acceptor systems Oxidation Stacking interactions

Nickel-catalyzed regioselective B(3,4,5,6)-H tetra-alkylation of o-carboranes

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中国科学:化学英文版 2023年第10期66卷 2836-2841页

作者： Jianwei Zhao Zuowei Xie department of chemistry and state key laboratory of synthetic chemistry The Chinese University of Hong KongHong Kong 999077China Shenzhen Grubbs Institute and department of chemistry Southern University of Science and TechnologyShenzhen 518055China

Though transition metal-catalyzed cage BH methylation has been well documented, catalytic alkylation of cage BH bonds remained elusive because transition metal alkyl complexes are prone to undergo β-H elimination. We report herein a highly efficient 8-aminoquinoline-assisted nickel-catalyzed regioselective cage B(3,4,5,6)-H tetra-alkylation of o-carboranes employing unactivated alkyl bromides as alkylating agents in the absence of any oxidants, leading to the preparation of a class of tetra-alkylated o-carboranes with a broad substrate scope in good to very high yields. This method opens new avenues for oxidant-free, direct, efficient, sustainable, and regioselective multiple B–H alkylation of carboranes via base metal catalysis.

关键词： nickel catalysis B-H activation carborane alkylation regioselectivity

Development of aspartic acid ligation for peptide cyclization derived from serine/threonine ligation

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Chinese Chemical Letters 2018年第7期29卷 1119-1122页

作者： Ci Xu Jianchao Xu Han Liu Xuechen Li department of chemistry State Key Laboratory of Synthetic ChemistryThe University of Hong Kong

Based on a mechanism analogous to the serine/threonine ligation, the aspartic acid ligation, which is facilitated by the γ-amino alcohol based ligation and oxidation, is developed and applied to the synthesis of cyclic peptides. The γ-hydroxyl group triggers the ring-chain tautomerization via a 6-endo-trig process,while the δ-hydroxyl group facilitates the oxidative cleavage of the vicinal diol to give carboxylic acid.

关键词： Aspartic acid ligation Peptide cyclization Serine/threonine ligation Ring-chain tautomerization Acyl transfer Selective oxidation

Recent advances on iron-catalyzed coupling reactions involving organolithium reagents

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Chinese Chemical Letters 2019年第8期30卷 1463-1467页

作者： Zhuliang Zhong Xiao-Shui Peng Henry N.C.Wong department of chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong Kong

Owing to their inexpensive and environmentally friendly properties,iron-based catalysts have been actively investigated for new organic reactions.In this account,we summarized our recent results on iron-catalyzed cross-coupling reactions and homo-coupling reactions.With iron-based catalysts,we constructed diverse carbon-carbon bonds,i.e.,C(sp^2)-C(sp^3),C(sp^3)-C(sp^3),C(sp^3)-C(sp^2)and C(sp^2)-C(sp^2)bonds.In order to demonstrate the usefulness of our iron protocol,we also carried out these reactions on gram-scale reactions,leading to good yields.

关键词： Iron-catalyzed Cross-coupling Homo-coupling Organolithium Gram-scale

How long a C–C bond can be? An example of extraordinary long C–C single bond in 1,2-diarylamino-o-carborane

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Chinese Chemical Letters 2019年第8期30卷 1530-1532页

作者： Yile Wu Jie Zhang Zuowei Xie department of chemistry and state key laboratory of synthetic chemistry The Chinese University of Hong Kong

How long a C-C bond can be?A question has long fascinated chemists.This work reports an example of extraordinary long C-C bond distance of 1.990(4)?observed in single-crystal X-ray structure of 1,2-(NHMes)2-o-carborane(2;Mes=2,4,6-trimethylphenyl).DFT calculations show that hyperconjugation of lone pairs of the nitrogen atoms into the emptyσ^*orbital of the cage C-C bond is the origin of the bond elongation.Such hyperconjugation can be suppressed if the two nitrogen atoms in 2 are linked to a Lewis acidic germanium(Ⅱ)center.

关键词： o-Carborane C–C single bond Hyperconjugation Amine X-ray structure

One-Pot Process to Carborano-Coumarin via Catalytic Cascade Dehydrogenative Cross-Coupling

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Chinese Journal of chemistry 2020年第4期38卷 383-388页

作者： Yik Ki Au Hairong Lyu Yangjian Quan Zuowei Xie Deportment of chemistry and state key laboratory of synthetic chemistry The Chinese University of Hong KongShatinN.T.Hong KongChina

Summary of main observation and conclusion Ir-catalyzed cascade dehydrogenative CH/BH and BH/OH cross-coupling of carboranyl carboxylic acid with readily available benzolc acid has been achieved,leading to the facile synthesis of previously unavailable carborano-coumarin in a simple one-pot process.Two cage B-H,one aryl C--H and one 0-H bonds are activated to construct eficiently new B-C and B-0 bonds.The cascade cyclization can stop at the first B-H/C-H cross-coupling step by tuning the reaction conditions,resulting in a series of a-carboranyl benzoic acid and aryl carborane derivatives.Control experiments indicate that B-H/C-H dehydrocoupling proceeds preferentially over B-H/O-H dehydrocoupling,and both directing groups and oxidants are crucial for this reaction.An iridium(V)intermediate is proposed to be involved in the catalytic cycle.

关键词： reaction. process. coupling

Intramolecular (4+3) cycloadditions of nitrogen-tethered epoxy enosilanes for the synthesis of heteropolycycles

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Chinese Chemical Letters 2019年第8期30卷 1523-1526页

作者： Jiayun He Shuk Mei Lam Jerome PLNg Wing-Tak Wong Pauline Chiu state key laboratory of synthetic chemistry Department of ChemistryThe University of Hong KongHong KongChina department of Applied Biology and Chemical Technology The Hong Kong Polytechnic UniversityHong KongChina

Furans bearing epoxy enolsilane units via a tether that incorporates a nitrogen heteroatom,undergo intramolecular(4+3)cycloadditions to generate bis-heteroatomic polycyclic adducts having piperidine moieties in their frameworks.The cycloadducts,ultimately derived from furfural,a renewal chemical feedstock,are obtained with up to 4:1 dr and with ee retained from the epoxide.

关键词： Heterocycles (4+3)cycloaddition Furan Intramolecular Epoxides Piperidine Polycyclic compounds

Rational design of platinum(Ⅱ)complexes with orthogonally oriented triazolyl ligand with emission enhancement characteristics for cancer chemotherapy in vivo

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Science China chemistry 2023年第10期66卷 2878-2884页

作者： Yeye Ai Zherui Zhang Yuexuan Fei Ruirong Ye Angela Sin-Yee Law Zong-Wan Mao Junqiu Liu Yongguang Li Vivian Wing-Wah Yam key laboratory of Organosilicon chemistry and Material Technology of Ministry of Education College of Material Chemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121China Institute of Molecular Functional Materials State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong KongHong KongChina School of chemistry Sun Yat-Sen UniversityGuangzhou 510275China state key laboratory of Supramolecular Structure and Materials Jilin UniversityChangchun 130012China

The mitochondria are essential for tumorigenesis and have been regarded as important targets in cancer chemotherapy.Herein,the mitochondria-targeted platinum(Ⅱ)complexes have been prepared.The introduction of the triazole group with larger steric hindrance through post-click reaction converts the hybridization of carbon from sp to sp^(2),endowing the complexes with an orthogonally oriented ligand with restricted rotation and emission enhancement characteristics.Methylation of the triazolyl ligand has led to platinum(Ⅱ)complexes that can efficiently enter cancer cells and selectively accumulate in mitochondria,leading to significant enhancement in phosphorescence.In vivo anti-cancer investigations have demonstrated their distinct antitumor efficacy in substantial inhibition of tumor growth in breast cancer mice through dissipation of mitochondrial membrane potential,inducing apoptosis of tumor cell with negligibly systemic cytotoxicity.

关键词： platinum(Ⅱ)complexes post-click reaction emission enhancement mitochondria-targeting antitumor

Modulating hydrothermal condition to achieve carbon dots-zeolite composites with multicolor afterglow

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Nano Research 2023年第5期16卷 7761-7769页

作者： Jiali Wen Zhifeng Zeng Bolun Wang Junyu hong Yingyuan Chen Jianyu Zhang Jiyang Li Jiuxing Jiang MOE key laboratory of Bioinorganic and synthetic chemistry School of ChemistrySun Yat-sen UniversityGuangzhou 510006China state key laboratory of Inorganic Synthesis and Preparative chemistry College of ChemistryJilin UniversityChangchun 130012China department of chemistry Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and ReconstructionThe Hong Kong University of Science and TechnologyKowloonHong Kong 999077China Guangdong Provincial key laboratory of Optical Chemicals XinHuaYue GroupMaoming 525000China

Responsive luminescence materials with prolonged lifetime and multicolor emission have drawn great attention due to their attractive optical property and potential applications.Herein,two responsive carbon dots(CDs)based composites:CD_(1)@MCM-22P and CD_(2)@ZSM-12 were achieved by a one-step hydrothermal method.By adjusting the hydrothermal condition,CD_(1)@MCM-22P owns temperature-dependent afterglow,while CD_(2)@ZSM-12 is equipped with excitation-dependent room-temperature phosphorescence.The photoluminescence mechanisms of CD1@MCM-22P and CD_(2)@ZSM-12 were investigated and proposed,and the composites were applied in multi-mode anti-counterfeiting.This work provides an insight as well as a feasible method for the development of multi-emissive CDs@zeolite composite.

关键词： carbon dots zeolitic matrices responsive photoluminescence room-temperature phosphorescence thermally activated delayed fluorescence