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Xu S, Wang Q, Rajeshkumar T, Jiang S, Maron L, Xu X. Reductive Dimerization of Alkenes and Allenes Enabled by Photochemically Activated Zinc-Zinc Bonded Compounds. J Am Chem Soc 2024. [PMID: 38957130 DOI: 10.1021/jacs.4c07390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Metal radicals have shown versatile reactivity in modern synthetic chemistry. However, the use of zinc radicals for molecular synthesis has been barely explored. Here, we show that a transient zinc radical can be formed through photoactivation of a zinc-zinc bonded compound, which is able to mediate the selective dimerization of alkenes and allenes. Treatment of dizinc compounds [L2Zn2] [L = CH3C(2,6-iPr2C6H3N)CHC(CH3)(NCH2CH2PR2); R = Ph (LPh) or iPr (LiPr)] with a diverse array of aromatic alkenes under UV irradiation (365 nm) facilely afforded the head-to-head coupling products, i.e., 1,4-dizinciobutanes in high yields. In addition, arylallenes could also be selectively dimerized by the dizinc compound to give 2,5-dizincyl-functionalized 1,5-hexadienes under the same conditions. Control reactions of [LPh2Zn2] in the presence of UV irradiation isolated a zinc phenyl complex and a trimeric zinc phosphide complex resulting from C-P bond cleavage at the tridentate ligand. Reactions of photoactivated dizinc compounds with organic spin traps, i.e., 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 2,2'-bipyridine (2,2'-bpy), successfully isolated zinc radical trapping products [LZnOTEMP] and [LPhZn(2,2'-bpy)·-], respectively. The profile of alkene dimerization was elucidated by density functional theory calculations, which confirmed that a transient zinc radical [LZn·] was initially generated through homolytic Zn-Zn bond cleavage via photoactivation followed by single-electron transfer and radical dimerization. The unique selectivity of the current reaction was also studied computationally.
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Affiliation(s)
- Shuilian Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Qiujie Wang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Thayalan Rajeshkumar
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, Toulouse 31077, France
| | - Shengjie Jiang
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
| | - Laurent Maron
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, Toulouse 31077, France
| | - Xin Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China
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N-alkyl-β-ketoiminate zinc complexes: Synthesis, structure, and reactivity in ring-opening polymerization of lactide. Inorganica Chim Acta 2023. [DOI: 10.1016/j.ica.2022.121253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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3
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Zhou S, Xu X, Zhu X, Zheng Y, Chen S, Xue M. A facile approach to C-functionalized β-ketoimine compounds via terminal alkylation of a tetralithiated intermediate. Org Biomol Chem 2022; 20:4289-4292. [PMID: 35574705 DOI: 10.1039/d2ob00640e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of C-functionalized β-ketoimine compounds at the terminal methyl groups of the β-ketoimine precursor LphH2 (Lph = C6H4[NC(Me)CHC(Me)O]2) were prepared. This convenient transformation was realized via straightforward double alkylation on the terminal Cα of a novel bis-dianionic β-ketoiminate lithium complex [Lph'Li4(THF)4]2 (Lph' = C6H4[NC(Me)CHC(O)CH2]2) followed by hydrolysis.
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Affiliation(s)
- Shuai Zhou
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Xiaojuan Xu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Xu Zhu
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Yu Zheng
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, China
| | - Sufang Chen
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
| | - Mingqiang Xue
- Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
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Cao F, Wang Y, Wang X, Zhang W, Solan GA, Wang R, Ma Y, Hao X, Sun WH. Zinc 8-aminotrihydroquinolines appended with pendant N-diphenylphosphinoethyl arms as exceptionally active catalysts for the ROP of ε-CL. Catal Sci Technol 2022. [DOI: 10.1039/d2cy00979j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Through activation with LiCH2SiMe3 or LiN(SiMe3)2, zinc(ii) chloride complexes bearing 5,6,7-trihydroquinolin-8-amines appended with pendant diphenyl phosphine units displayed remarkable catalytic activity for ROP of ε-caprolactone.
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Affiliation(s)
- Furong Cao
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing Institute of Fashion Technology, Beijing 100029, China
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yun Wang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing Institute of Fashion Technology, Beijing 100029, China
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xing Wang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing Institute of Fashion Technology, Beijing 100029, China
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenjuan Zhang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing Institute of Fashion Technology, Beijing 100029, China
| | - Gregory A. Solan
- Department of Chemistry, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - Rui Wang
- Beijing Key Laboratory of Clothing Materials R&D and Assessment, Beijing Engineering Research Center of Textile Nanofiber, School of Materials Science and Engineering, Beijing Institute of Fashion Technology, Beijing 100029, China
| | - Yanping Ma
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiang Hao
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wen-Hua Sun
- Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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Janoszka N, Azhdari S, Hils C, Coban D, Schmalz H, Gröschel AH. Morphology and Degradation of Multicompartment Microparticles Based on Semi-Crystalline Polystyrene- block-Polybutadiene- block-Poly( L-lactide) Triblock Terpolymers. Polymers (Basel) 2021; 13:polym13244358. [PMID: 34960909 PMCID: PMC8706259 DOI: 10.3390/polym13244358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/24/2022] Open
Abstract
The confinement assembly of block copolymers shows great potential regarding the formation of functional microparticles with compartmentalized structure. Although a large variety of block chemistries have already been used, less is known about microdomain degradation, which could lead to mesoporous microparticles with particularly complex morphologies for ABC triblock terpolymers. Here, we report on the formation of triblock terpolymer-based, multicompartment microparticles (MMs) and the selective degradation of domains into mesoporous microparticles. A series of polystyrene-block-polybutadiene-block-poly(L-lactide) (PS-b-PB-b-PLLA, SBL) triblock terpolymers was synthesized by a combination of anionic vinyl and ring-opening polymerization, which were transformed into microparticles through evaporation-induced confinement assembly. Despite different block compositions and the presence of a crystallizable PLLA block, we mainly identified hexagonally packed cylinders with a PLLA core and PB shell embedded in a PS matrix. Emulsions were prepared with Shirasu Porous Glass (SPG) membranes leading to a narrow size distribution of the microparticles and control of the average particle diameter, d ≈ 0.4 µm–1.8 µm. The core–shell cylinders lie parallel to the surface for particle diameters d < 0.5 µm and progressively more perpendicular for larger particles d > 0.8 µm as verified with scanning and transmission electron microscopy and particle cross-sections. Finally, the selective degradation of the PLLA cylinders under basic conditions resulted in mesoporous microparticles with a pronounced surface roughness.
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Affiliation(s)
- Nicole Janoszka
- Physical Chemistry, Center for Soft Nanoscience (SoN) and Center for Nanotechnology (CeNTech), University of Münster, Corrensstraße 28-30, 48149 Münster, Germany; (N.J.); (S.A.); (D.C.)
| | - Suna Azhdari
- Physical Chemistry, Center for Soft Nanoscience (SoN) and Center for Nanotechnology (CeNTech), University of Münster, Corrensstraße 28-30, 48149 Münster, Germany; (N.J.); (S.A.); (D.C.)
| | - Christian Hils
- Macromolecular Chemistry II, University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany;
| | - Deniz Coban
- Physical Chemistry, Center for Soft Nanoscience (SoN) and Center for Nanotechnology (CeNTech), University of Münster, Corrensstraße 28-30, 48149 Münster, Germany; (N.J.); (S.A.); (D.C.)
| | - Holger Schmalz
- Macromolecular Chemistry II, University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany;
- Bavarian Polymer Institute (BPI), University of Bayreuth, Universitätsstraße 30, 95440 Bayreuth, Germany
- Correspondence: (H.S.); (A.H.G.)
| | - André H. Gröschel
- Physical Chemistry, Center for Soft Nanoscience (SoN) and Center for Nanotechnology (CeNTech), University of Münster, Corrensstraße 28-30, 48149 Münster, Germany; (N.J.); (S.A.); (D.C.)
- Correspondence: (H.S.); (A.H.G.)
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