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Dissanayake D, Forsyth C, Vidović D. Synthesis, characterisation and reactivity studies of chiral β-diketiminate-like supported aluminium Lewis acid complexes towards difficult Diels Alder cycloadditions. Dalton Trans 2023; 52:4063-4076. [PMID: 36880570 DOI: 10.1039/d3dt00206c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Synthesis and characterisation of several chiral, oxazoline containing β-diketiminate type ligand supported-aluminium compounds are reported. Together with 1 equiv. of Na(BArCl4) (ArCl = 3,5-Cl2-C6H3), these chiral Lewis acid complexes, which possess an "achiral end" and "chiral end" have been successfully utilised as catalysts in asymmetric Diels-Alder reactions of 1,3-cyclohexadiene and several different chalcones. Systematic increase in the steric demand of the ligand's "achiral end" of these complexes resulted in enhanced enantioinduction for the cyclisation of 1,3-cyclohexadiene and chalcone. Further structural modifications of the "chiral end" clearly established that having a tert-butyl group connected to the stereogenic centre of the oxazoline fragment yielded the highest enantioselectivity value for the examined cyclisation. A substrate scope was then expanded using several different dienophiles (i.e. chalcones) generating an enantiomeric excess range of 24-68%.
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Affiliation(s)
| | - Craig Forsyth
- School of Chemistry, Monash University, Wellington Rd, Clayton VIC 3800, Australia.
| | - Dragoslav Vidović
- School of Chemistry, Monash University, Wellington Rd, Clayton VIC 3800, Australia.
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Hu M, Song X, Wang F, Zhang W, Ma W, Han F. Ring-opening polymerization of rac-lactide catalyzed by magnesium and zinc complexes supported by an NNO ligand. NEW J CHEM 2022. [DOI: 10.1039/d1nj05157a] [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
Preparation of magnesium and zinc complexes containing unsymmetric tertiary amine ligands and their catalytic properties for polymerization of rac-lactide.
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Affiliation(s)
- Minggang Hu
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
- Heilongjiang Provincial Key Laboratory of Catalytic Synthesis for Fine Chemicals, Qiqihar University, Qiqihar, 161006, China
| | - Xinfeng Song
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Fugui Wang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Wenzhi Zhang
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Wenhui Ma
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
| | - Fuzhong Han
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar, 161006, China
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Liu Y, Yuan X, Wu J, Hu X, Zhu N, Guo K. Access to high-molecular-weight poly(γ-butyrolactone) by using simple commercial catalysts. Polym Chem 2022. [DOI: 10.1039/d1py01340h] [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
The simple commercial organomagnesium catalysts were utilized for efficient access to high-molecular-weight poly(γ-butyrolactone) and facile manipulation of the reaction conditions enabled the polymer topology controlled.
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Affiliation(s)
- Yihuan Liu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Xin Yuan
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Jiaqi Wu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Xin Hu
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
- College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Ning Zhu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
| | - Kai Guo
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211800, China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 211800, China
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Gauld RM, Lynch JR, Kennedy AR, Barker J, Reid J, Mulvey RE. Expected and Unexpected Reactivities of Homoleptic LiNacNac and Heteroleptic NacNacMg(TMP) β-Diketiminates toward Various Small Unsaturated Organic Molecules. Inorg Chem 2021; 60:6057-6064. [PMID: 33830739 PMCID: PMC8154426 DOI: 10.1021/acs.inorgchem.1c00549] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Homoleptic LiNacNac forms simple donor-acceptor complexes with N,N'-dicyclohexylcarbodiimide (CyN═C═NCy), triphenylphosphine oxide (Ph3P═O), and benzophenone (Ph2CO). These crystallographically characterized compounds could be regarded as model intermediates en route to reducing the N═C, P═O, and C═O bonds of unsaturated substrates. Heteroleptic NacNacMg(TMP) intriguingly functions as a TMP nucleophile both with t-BuNCO and t-BuNCS, producing a urea or thiourea derivative respectively attached to Mg, though the NacNac ligand in the former reaction also engages noninnocently with a second t-BuNCO molecule via insertion at the reactive NacNac backbone γ-carbon site.
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Affiliation(s)
- Richard M Gauld
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Jennifer R Lynch
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
| | - Jim Barker
- Innospec Ltd., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire CH65 4EY, U.K
| | - Jacqueline Reid
- Innospec Ltd., Innospec Manufacturing Park, Oil Sites Road, Ellesmere Port, Cheshire CH65 4EY, U.K
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K
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Rinke P, Görls H, Kretschmer R. Calcium and Magnesium Bis(β-diketiminate) Complexes: Impact of the Alkylene Bridge on Schlenk-Type Rearrangements. Inorg Chem 2021; 60:5310-5321. [PMID: 33667337 DOI: 10.1021/acs.inorgchem.1c00301] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Dinuclear heteroleptic alkaline-earth-metal complexes are interesting synthetic targets because the close proximity of two metals allows for cooperative effects. However, these complexes are also prone to undergoing Schlenk-type rearrangements, affording less-active homoleptic complexes. Here we present the metalation of bis(β-diketimine) ligands possessing flexible bridging groups, i.e., 1,2-ethylene, 1,3-propylene, and trans-1,2-cyclohexylene, using calcium and magnesium precursors. Four mononuclear homoleptic calcium complexes were obtained, highlighting the pronounced tendency of calcium to undergo Schlenk-like redistributions. In the case of magnesium, however, the bridging group plays a crucial role, yielding seven dinuclear heteroleptic complexes but also one mononuclear and one dinuclear homoleptic complexes. In addition, a trinuclear mixed heteroleptic-homoleptic magnesium complex, which is a rare example of an intermediate of the Schlenk equilibrium, was isolated.
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Affiliation(s)
- Philipp Rinke
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany
| | - Robert Kretschmer
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, 07743 Jena, Germany.,Jena Center for Soft Matter, Friedrich Schiller University Jena, Philosophenweg 7, 07743 Jena, Germany
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de Bruin-Dickason CN, Rosengarten CA, Deacon GB, Jones C. Enantiopure dimagnesium(i) and magnesium(ii) hydride complexes incorporating chiral amidinate or β-diketiminate ligands. Chem Commun (Camb) 2021; 57:1599-1602. [PMID: 33459330 DOI: 10.1039/d0cc07947b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A known chiral β-diketiminate, [HC{MeCN-(S)-(-)-CHMePh}(MeCNDip)]- (Dip = 2,6-diisopropylphenyl) L1, and a new chiral amidinate, [ButC(NAr*){N-(S)-(-)-CHMePh}]- L2 (Ar* = C6H2{C(H)Ph2}2Me-2,6,4) have been utilised in the synthesis of the first examples of enantiopure, dinuclear magnesium(i), [(L1)Mg-Mg(L1)], and magnesium(ii) hydride complexes, [(L2)Mg(μ-H)2Mg(L2)] and [(L2)(THF)Mg(μ-H)2Mg(THF)(L2)]. A related enantiopure β-diketiminato magnesium hydride cluster compound, [(L1)4Mg5H6], has also been synthesised, presumably forming via a partial redistribution of in situ generated [(L1)Mg(μ-H)2Mg(L1)].
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