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Reddy GS, Corey EJ. Synthesis of Tetracyclic C2-Symmetric Ketiminium Salts and Evaluation as Catalysts for Epoxidation. Org Lett 2023; 25:3539-3542. [PMID: 37140440 DOI: 10.1021/acs.orglett.3c01123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Short synthetic routes to the nonplanar tetracyclic ketiminium salt A and two close analogs are described. These are helical nonplanar structures as shown by X-ray crystallography.
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Affiliation(s)
- G Sudhakar Reddy
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - E J Corey
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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2
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Li S, Cao Y, Dong H. Solvent polarity dependent excited state behaviors for 2‐(2‐hydroxyphenyl) benzothiazole‐5‐(9H‐carbazol‐9‐yl)phenol fluorophore: A theoretical study. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Songtao Li
- Hebei Key Laboratory of Physics and Energy Technology, Department of Mathematics and Physics North China Electric Power University Baoding China
| | - Yahui Cao
- Hebei Key Laboratory of Physics and Energy Technology, Department of Mathematics and Physics North China Electric Power University Baoding China
| | - Hao Dong
- Hebei Key Laboratory of Physics and Energy Technology, Department of Mathematics and Physics North China Electric Power University Baoding China
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3
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D'Arcy TD, Elsegood MRJ, Buckley BR. Organocatalytic Enantioselective Synthesis of Bicyclo[2.2.2]octenones via Oxaziridinium Catalysed
ortho
‐Hydroxylative Phenol Dearomatization**. Angew Chem Int Ed Engl 2022; 61:e202205278. [PMID: 35543699 PMCID: PMC9401573 DOI: 10.1002/anie.202205278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Indexed: 11/12/2022]
Abstract
Hydroxylative dearomatization reactions of phenols (HPD) offer an efficient way to assemble complex, biologically relevant scaffolds. Despite this, enantioselective hydroxylative phenol dearomatizations for the construction of bicyclo[2.2.2]octenones are classically limited to stoichiometric chiral reagents, and a practical, enantioselective catalytic method has remained elusive. Herein, we describe a highly enantioselective, organocatalytic tandem o‐HPD‐[4+2] reaction. Our methodology utilizes a chiral oxaziridinium organocatalyst, that is available in both enantiomeric forms, to afford dearomatized products in high enantioselectivity over a range of phenol substitution patterns. This approach was applied to the highly enantioselective synthesis of (+)‐biscarvacrol (99 : 1 e.r.) and (−)‐bis(2,6‐xylenol) (94 : 6 e.r.). The practicality of our conditions was demonstrated at gram‐scale, using an amine precatalyst, accessible in a single synthetic step.
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Affiliation(s)
- Tom D. D'Arcy
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
| | - Mark R. J. Elsegood
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
| | - Benjamin R. Buckley
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
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4
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D'Arcy TD, Elsegood MRJ, Buckley BR. Organocatalytic Enantioselective Synthesis of Bicyclo[2.2.2]octenones via Oxaziridinium Catalysed
ortho
‐Hydroxylative Phenol Dearomatization**. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202205278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tom D. D'Arcy
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
| | - Mark R. J. Elsegood
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
| | - Benjamin R. Buckley
- Department of Chemistry Loughborough University Loughborough, Leicestershire LE11 3TU UK
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5
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Auras S, Trapp O. Scorpio‐Ligand: Synthesis of Biphenyl‐Dihydroazepine Phosphoramidite Ligands for Asymmetric Hydrogenation. Helv Chim Acta 2021. [DOI: 10.1002/hlca.202100147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stefanie Auras
- Department of Chemistry Ludwig Maximilian University Munich Butenandtstr. 5–13 DE-81377 Munich Germany
| | - Oliver Trapp
- Department of Chemistry Ludwig Maximilian University Munich Butenandtstr. 5–13 DE-81377 Munich Germany
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6
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Estruch-Blasco M, Bosque I, Guijarro D, Gonzalez-Gomez JC. Electrochemically site-selective alkoxylation of twisted 2-arylbenzoic acids via spirolactonization. Org Chem Front 2021. [DOI: 10.1039/d1qo00834j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Twisted σ-biphenyl-2-carboxyl radicals show a significant spin density in the adjacent aryl ring, facilitating the spirocyclization. Electro-cross coupling with alcohols and isomerization provide a site-selective alkoxylation of 2-arylbenzoic acids.
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Affiliation(s)
- Manel Estruch-Blasco
- Instituto de Síntesis Orgánica (ISO) and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
| | - Irene Bosque
- Instituto de Síntesis Orgánica (ISO) and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
| | - David Guijarro
- Instituto de Síntesis Orgánica (ISO) and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
| | - Jose C. Gonzalez-Gomez
- Instituto de Síntesis Orgánica (ISO) and Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Alicante, Apdo. 99, 03080 Alicante, Spain
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7
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Tarasenko MV, Presnukhina SI, Baikov SV, Shetnev AA. Synthesis and Evaluation of Antibacterial Activity of 1,2,4-Oxadiazole-Containing Biphenylcarboxylic Acids. RUSS J GEN CHEM+ 2020. [DOI: 10.1134/s1070363220090042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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8
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Wang F, Meng XG, Wu YY, Huang H, Lv J, Yu WW. A Highly Efficient Heterogeneous Catalyst of Bimetal-Organic Frameworks for the Epoxidation of Olefin with H 2O 2. Molecules 2020; 25:E2389. [PMID: 32455583 PMCID: PMC7287932 DOI: 10.3390/molecules25102389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/09/2020] [Accepted: 01/15/2020] [Indexed: 11/16/2022] Open
Abstract
A series of bimetel organic framework MnxCu1-x-MOF were prepared. The MOFs was characterized and analyzed by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The catalytic activity of the developed catalyst was tested on various olefins by H2O2 as oxidant. The MOFs catalyst exhibits excellent catalytic activity for the epoxidations of various aromatic and cyclic olefins. Particularly, Mn0.1Cu0.9-MOF can achieve 90.2% conversion of styrene with 94.3% selectivity of styrene oxide at 0 °C after reaction 6 h. The MOF exhibited the catalytic activity of inverse temperature effect on epoxidation of styrene. The introduction of copper component can stabilize H2O2 and inhibit its decomposition to a certain extent. The catalyst can be reused at least five cycles without significant loss in activity towards epoxidation.
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Affiliation(s)
| | - Xiang-Guang Meng
- Key Laboratory of Green Chemistry and Technology, College of Chemistry, Sichuan University, Chengdu 610064, China; (F.W.); (Y.-Y.W.); (H.H.); (J.L.); (W.-W.Y.)
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9
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Huang J, Liu S, Ma Y, Cai J. Chiral salen Mn (III) immobilized on ZnPS-PVPA through alkoxyl-triazole for superior performance catalyst in asymmetric epoxidation of unfunctionalized olefins. J Organomet Chem 2019. [DOI: 10.1016/j.jorganchem.2019.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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10
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Bulman Page PC, Almutairi SM, Chan Y, Stephenson GR, Gama Y, Goodyear RL, Douteau A, Allin SM, Jones GA. Asymmetric Oxidation of Enol Derivatives to α-Alkoxy Carbonyls Using Iminium Salt Catalysts: A Synthetic and Computational Study. J Org Chem 2019; 84:544-559. [PMID: 30548068 DOI: 10.1021/acs.joc.8b02354] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We report herein the first examples of asymmetric oxidation of enol ether and ester substrates using iminium salt organocatalysis, affording moderate to excellent enantioselectivities of up to 98% ee for tetralone-derived substrates in the α-hydroxyketone products. A comprehensive density functional theory study was undertaken to interpret the competing diastereoisomeric transition states in this example in order to identify the origins of enantioselectivity. The calculations, performed at the B3LYP/6-31G(D) level of theory, gave good agreement with the experimental results, in terms of the magnitude of the effects under the specified reaction conditions, and in terms of the preferential formation of the ( R)-enantiomer. Just one of the 30 characterized transition states dominates the enantioselectivity, which is attributed to the adoption of an orientation relative to stereochemical features of the chiral controlling element that combines a CH-π interaction between a CH2 group in the substrate and one of the aromatic rings of the biaryl section of the chiral auxiliary with a good alignment of the acetoxy group with the other biaryl ring, and places the smallest substituent on the alkene (a hydrogen atom) in the most sterically hindered position.
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Affiliation(s)
- Philip C Bulman Page
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Saud M Almutairi
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Yohan Chan
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - G Richard Stephenson
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Yannick Gama
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Ross L Goodyear
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Alice Douteau
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
| | - Steven M Allin
- Department of Chemistry and Forensics , Nottingham Trent University , Clifton , Nottingham NG11 8NS , U.K
| | - Garth A Jones
- School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , Norfolk NR4 7TJ , U.K
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11
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Bulman Page PC, Kinsey FS, Chan Y, Strutt IR, Slawin AMZ, Jones GA. Novel binaphthyl and biphenyl α- and β-amino acids and esters: organocatalysis of asymmetric Diels-Alder reactions. A combined synthetic and computational study. Org Biomol Chem 2018; 16:7400-7416. [PMID: 30259945 DOI: 10.1039/c8ob01795f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Asymmetric catalysis of the Diels-Alder reaction between cyclopentadiene and cinnamaldehydes has been studied using as catalysts a range of novel α- and β-aminoacids and aminoesters with binaphthyl and biphenyl backbones, providing enantioselectivities of up to 62% ee. B3LYP/6-31G* calculations, including free energy corrections, have been carried out on a binaphthyl catalyst example to identify transition state structures and to aid in the identification of major enantiomers. The calculated product ratios agree well with the experimental data; the transition states identified involve preferential approach of cyclopentene along a trajectory adjacent to the acid/ester group. The four lowest energy transition states display a stabilizing dipolar interaction between the carbonyl group oxygen atom and a terminal proton of the diene unit.
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Affiliation(s)
- Philip C Bulman Page
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK.
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12
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Boichenko MA, Chagarovskiy AO. Recent achievements in the synthesis of dibenz[c,e]azepines (microreview). Chem Heterocycl Compd (N Y) 2018. [DOI: 10.1007/s10593-018-2207-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Balgobin SMC, Brookes DJ, Jiang J, Pritchard RG, Wallace TW. Axial stereocontrol in tropos dibenz[c,e]azepines: the individual and cooperative effects of alkyl substituents. Org Biomol Chem 2017; 15:10184-10199. [PMID: 29177299 DOI: 10.1039/c7ob02385e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
6,7-Dihydro-5H-dibenz[c,e]azepines, a class of secondary amine incorporating a centre-axis chirality relay, can be prepared from N-(2-bromobenzyl)-N-(1-arylalkyl)methanesulfonamides via Pd-catalysed intramolecular direct arylation, and methylated at C(7) via the 5,7-trans diastereoselective addition of methylmagnesium bromide to the derived N-benzylazepinium tetraphenylborate. Using these methods, the 4,5-dimethylated and 4,5,7-trimethylated homologues 13 and 14 were obtained and shown by 1H NMR spectroscopy to be axially biased in opposite senses, as defined by the respective pseudoaxial or pseudoequatorial orientation of the 5-substituent in the preferred conformers, while retaining their tropos nature (the Arrhenius activation energy, EA, for the conformational exchange process in 14 was estimated to be 57 kJ mol-1 using 2D-EXSY NMR spectroscopy at 233-248 K). These results serve to illustrate how substituent effects might be exploited in new designs of bridged biaryl ligand in which tropos dynamics operate in combination with a pre-existing axial stereochemical bias.
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Affiliation(s)
- Sinead M C Balgobin
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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14
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Bulman Page PC, Chan Y, Noor Armylisas AH, Alahmdi M. Asymmetric epoxidation of chromenes mediated by iminium salts: Synthesis of mollugin and (3S,4R)-trans-3,4-dihydroxy-3,4-dihydromollugin. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.10.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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15
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Day DP, Sellars PB. Recent Advances in Iminium-Salt-Catalysed Asymmetric Epoxidation. European J Org Chem 2016. [DOI: 10.1002/ejoc.201600908] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- David P. Day
- Department of Chemistry; University of Warwick; CV4 7AL Coventry U.K
| | - Philip B. Sellars
- Department of Chemistry; University of Warwick; CV4 7AL Coventry U.K
- WMG; University of Warwick; CV4 7AL Coventry U.K
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