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Kuan TH, Hou DR. Synthesis of 2-Aryl Acetophenones via Hydrobromination and Oxy-isomerization of ( o-Arylethynyl)benzyl Alcohols. J Org Chem 2021; 86:6907-6917. [PMID: 33852296 DOI: 10.1021/acs.joc.1c00294] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrobromination and oxy-isomerization of (o-arylethynyl)benzyl alcohols to yield brominated aryl ketones were achieved with bromotrimethylsilane. The substrate scope suggested that vinyl carbocations, stabilized by the conjugated aryl groups, are the reaction intermediates. 1H-Isochromene was also detected by 1H NMR, and an isolated 1H-isochromene was converted to the product when retreated with TMSBr. The formation of 1H-isochromene is equivalent to a 6-endo-dig cyclization and contrasts with the corresponding reactions under basic conditions, in which the 5-exo-dig process dominated.
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Affiliation(s)
- Tzu-Hsuan Kuan
- Department of Chemistry, National Central University, No. 300 Jhong-Da Road, Jhong-li, Taoyuan 32001, Taiwan
| | - Duen-Ren Hou
- Department of Chemistry, National Central University, No. 300 Jhong-Da Road, Jhong-li, Taoyuan 32001, Taiwan
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2
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Liu J, Chen M. Enantioselective anti- and syn-(Borylmethyl)allylation of Aldehydes via Brønsted Acid Catalysis. Org Lett 2020; 22:8967-8972. [PMID: 33125249 DOI: 10.1021/acs.orglett.0c03366] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The enantioselective anti- and syn-(borylmethyl)allylation of aldehydes via phosphoric acid catalysis is reported. Both (E)- and (Z)-γ-borylmethyl allylboronate reagents were prepared via the Cu-catalyzed highly stereoselective protoboration of 1,3-dienylboronate. Chiral phosphoric acid-catalyzed aldehyde allylation with either the (E)- or (Z)-allylboron reagent provided 1,2-anti- or 1,2-syn-adducts in good yields with high enantioselectivities. The application to the synthesis of morinol D was accomplished.
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Affiliation(s)
- Jiaming Liu
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
| | - Ming Chen
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849, United States
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3
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Bhim A, Sasmal S, Gopalakrishnan J, Natarajan S. Visible-Light-Activated C-C Bond Cleavage and Aerobic Oxidation of Benzyl Alcohols Employing BiMXO 5 (M=Mg, Cd, Ni, Co, Pb, Ca and X=V, P). Chem Asian J 2020; 15:3104-3115. [PMID: 32790062 DOI: 10.1002/asia.202000814] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/07/2020] [Indexed: 11/10/2022]
Abstract
The synthesis, structure, optical and photocatalytic studies of a family of compounds with the general formula, BiMXO5 ; M=Mg, Cd, Ni, Co, Pb, Ca and X=V, P is presented. The compounds were prepared by regular solid-state reaction of constituents in the temperature range of 720-810 °C for 24 h. The compounds were characterized by powder X-ray diffraction (PXRD) methods. The Rietveld refinement of the PXRD patterns have been carried out to establish the structure. The optical absorption spectra along with the colors in daylight have been explained employing the allowed d-d transition. In addition, the observed colors of some of the V5+ containing compounds were explained using metal-to-metal charge transfer (MMCT) from the partially filled transition-metal 3d orbitals to the empty 3d orbitals of V5+ ions. The near IR (NIR) reflectivity studies indicate that many compounds exhibit good NIR reflectivity, suggesting that these compounds can be employed as 'cool pigments'. The experimentally determined band gaps of the prepared compounds were found to be suitable to exploit them for visible light activated photocatalysis. Photocatalytic C-C bond cleavage of alkenes and aerobic oxidation of alcohols were investigated employing visible light, which gave good yields and selectivity. The present study clearly demonstrated the versatility of the Paganoite family of compounds (BiMXO5 ) towards new colored inorganic materials, visible-light photocatalysts and 'cool pigments'.
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Affiliation(s)
- Anupam Bhim
- Framework Solids Laboratory, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Shreya Sasmal
- Framework Solids Laboratory, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Jagannatha Gopalakrishnan
- Framework Solids Laboratory, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
| | - Srinivasan Natarajan
- Framework Solids Laboratory, Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, 560012, India
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4
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Wrzeszcz Z, Siedlecka R. Heteroaromatic N-Oxides in Asymmetric Catalysis: A Review. Molecules 2020; 25:molecules25020330. [PMID: 31947566 PMCID: PMC7024222 DOI: 10.3390/molecules25020330] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 11/18/2022] Open
Abstract
An increasing interest in the synthesis and use of optically active pyridine N-oxides as chiral controllers for asymmetric reactions has been observed in the last few years. Chiral heteroaromatic N-oxides can work as powerful electron-pair donors, providing suitable electronic environments in the transition state formed within the reaction. The nucleophilicity of the oxygen atom in N-oxides, coupled with a high affinity of silicon to oxygen, represent ideal properties for the development of synthetic methodology based on nucleophilic activation of organosilicon reagents. The application of chiral N-oxides as efficient organocatalysts in allylation, propargylation, allenylation, and ring-opening of meso-epoxides, as well as chiral ligands for metal complexes catalyzing Michael addition or nitroaldol reaction, can also be found in the literature. This review deals with stereoselective applications of N-oxides, and how the differentiating properties are correlated with their structure. It contains more recent results, covering approximately the last ten years. All the reported examples have been divided into five classes, according to the chirality elements present in their basic molecular frameworks.
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5
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Ulč J, Nečas D, Koukal P, Havlíček V, Tošner Z, Hybelbauerová S, Kotora M. Chiral Unsymmetrically Substituted Bipyridine N
,N′
-Dioxides as Catalysts for the Allylation of Aldehydes. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800485] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Jan Ulč
- Department of Organic Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - David Nečas
- Department of Organic Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - Petr Koukal
- Department of Organic Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - Vojtěch Havlíček
- Department of Organic Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - Zdeněk Tošner
- NMR Laboratory; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - Simona Hybelbauerová
- Department of Teaching and Didactics of Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
| | - Martin Kotora
- Department of Organic Chemistry; Faculty of Science; Charles University; Hlavova 8 123 43 Praha 2 Czech Republic
- Institute of Organic Chemistry and Biochemistry; Czech Academy of Sciences; Flemingovo nám. 2 166 10 Prague 6 Czech Republic
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6
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Unsworth CA, Coulson B, Chechik V, Douthwaite RE. Aerobic oxidation of benzyl alcohols to benzaldehydes using monoclinic bismuth vanadate nanoparticles under visible light irradiation: Photocatalysis selectivity and inhibition. J Catal 2017. [DOI: 10.1016/j.jcat.2017.08.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Venkateshwarlu R, Chinnababu B, Ramulu U, Purushotham Reddy K, Damoder Reddy M, Sowjanya P, Venkateswara Rao P, Aravind S. Synthesis and biological evaluation of (-)-kunstleramide and its derivatives. MEDCHEMCOMM 2017; 8:394-404. [PMID: 30108756 PMCID: PMC6071945 DOI: 10.1039/c6md00606j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 12/08/2016] [Indexed: 01/28/2023]
Abstract
Stereoselective total synthesis of (-)-kunstleramide, a cytotoxic dienamide from the bark of Beilschmiedia kunstleri gamble, has been accomplished by using Keck's asymmetric allylation and Trost isomerization as key reactions. Application of the developed strategy for the synthesis of a series of amide analogues (8-22) was also reported. Furthermore, the synthesized compounds were evaluated for their in vitro anti-proliferative activities against human epithelial lung carcinoma (A549), human epithelial cervical cancer (HeLa), human breast adenocarcinoma (MCF7) and human neuroblastoma (IMR32) cell lines using the SRB assay. All the compounds show moderate anti-proliferative activity against all cell lines. Some of the piperazine derivatives (17-22) strongly inhibit the growth of breast cancer cells with IC50 values of 8-20 μM.
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Affiliation(s)
- R Venkateshwarlu
- Department of Chemistry , Osmania University , Hyderabad , Telangana State , India-500007 . ;
| | - B Chinnababu
- Division of Natural Product Chemistry , CSIR-IICT , Hyderabad , Telangana State , India-500007
| | - U Ramulu
- Division of Natural Product Chemistry , CSIR-IICT , Hyderabad , Telangana State , India-500007
| | - K Purushotham Reddy
- Division of Natural Product Chemistry , CSIR-IICT , Hyderabad , Telangana State , India-500007
| | - M Damoder Reddy
- Department of Pharmaceutical Sciences , School of Pharmacy , Union University , 1050 Union University Drive , Jackson , Tennessee , USA-38305
| | - P Sowjanya
- Division of Chemical Biology , CSIR-IICT , Hyderabad , Telangana State , India-500007
| | - P Venkateswara Rao
- Department of Chemistry , Osmania University , Hyderabad , Telangana State , India-500007 . ;
| | - S Aravind
- Department of Chemistry , Osmania University , Hyderabad , Telangana State , India-500007 . ;
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8
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Pyridine N-Oxides and Derivatives Thereof in Organocatalysis. TOPICS IN HETEROCYCLIC CHEMISTRY 2017. [DOI: 10.1007/7081_2017_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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9
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Volpin G, Vepřek NA, Bellan AB, Trauner D. Enantioselektive Synthese und Racemisierung von (−)‐Sinoracutin. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201608206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Giulio Volpin
- Department of Chemistry Ludwig-Maximilians-Universität München 81377 München Deutschland
| | - Nynke A. Vepřek
- Department of Chemistry Ludwig-Maximilians-Universität München 81377 München Deutschland
| | - Andreas B. Bellan
- Department of Chemistry Ludwig-Maximilians-Universität München 81377 München Deutschland
| | - Dirk Trauner
- Department of Chemistry Ludwig-Maximilians-Universität München 81377 München Deutschland
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10
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Volpin G, Vepřek NA, Bellan AB, Trauner D. Enantioselective Synthesis and Racemization of (-)-Sinoracutine. Angew Chem Int Ed Engl 2016; 56:897-901. [PMID: 27990734 DOI: 10.1002/anie.201608206] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Indexed: 11/12/2022]
Abstract
Sinoracutine is a recently isolated alkaloid with unusual stereochemical and biological properties. It features an unprecedented tetracyclic 6/6/5/5 skeleton that bears an N-methylpyrrolidine ring fused to a cyclopentenone. Interestingly, both enantiomers of sinoracutine have been independently isolated from the same plant, yet the molecule does not appear to occur as a racemate. Here, we present a short synthesis of (-)-sinoracutine that relies on a highly diastereoselective Pauson-Khand reaction and a Mandai-Claisen reaction to install the quaternary stereocenter. Our work establishes the absolute configuration of the levorotatory isomer and suggests that the optical purity of sinoracutine varies in nature due to its gradual racemization. Experimental evidence supports this proposal, and a plausible mechanism for the racemization is provided.
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Affiliation(s)
- Giulio Volpin
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377, Munich, Germany
| | - Nynke A Vepřek
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377, Munich, Germany
| | - Andreas B Bellan
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377, Munich, Germany
| | - Dirk Trauner
- Department of Chemistry, Ludwig-Maximilians-Universität München, 81377, Munich, Germany
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11
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Rodríguez E, Grayson MN, Asensio A, Barrio P, Houk KN, Fustero S. Chiral Brønsted Acid-Catalyzed Asymmetric Allyl(propargyl)boration Reaction of ortho-Alkynyl Benzaldehydes: Synthetic Applications and Factors Governing the Enantioselectivity. ACS Catal 2016. [DOI: 10.1021/acscatal.6b00209] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Elsa Rodríguez
- Departamento
de Química Orgánica, Universidad de Valencia, Av. Vicente
Andrés Estellés s/n, E-46100 Burjassot, Spain
| | - Matthew N. Grayson
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Amparo Asensio
- Departamento
de Química Orgánica, Universidad de Valencia, Av. Vicente
Andrés Estellés s/n, E-46100 Burjassot, Spain
| | - Pablo Barrio
- Departamento
de Química Orgánica, Universidad de Valencia, Av. Vicente
Andrés Estellés s/n, E-46100 Burjassot, Spain
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Santos Fustero
- Departamento
de Química Orgánica, Universidad de Valencia, Av. Vicente
Andrés Estellés s/n, E-46100 Burjassot, Spain
- Laboratorio
de Moléculas Orgánicas, Centro de Investigación Príncipe Felipe, E-46012 Valencia, Spain
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12
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Calder EDD, Sutherland A. Enantioselective Synthesis of 3-Methyleneindan-1-ols via a One-Pot Allylboration–Heck Reaction of 2-Bromobenzaldehydes. Org Lett 2015; 17:2514-7. [PMID: 25933177 DOI: 10.1021/acs.orglett.5b01047] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ewen D. D. Calder
- WestCHEM, School of Chemistry, The Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, U.K
| | - Andrew Sutherland
- WestCHEM, School of Chemistry, The Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, U.K
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13
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Hemelaere R, Carreaux F, Carboni B. A Diastereoselective Route totrans-2-Aryl-2,3-dihydrobenzofurans through Sequential Cross-Metathesis/Isomerization/Allylboration Reactions: Synthesis of Bioactive Neolignans. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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