1
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Abstract
A concise enantioselective total synthesis of the neoclerodane diterpene (-)-salvinorin A is reported. The stereogenic center at C-12 was installed by catalytic asymmetric propargylation with excellent enantioselectivity, and the remaining six stereogenic centers were set up highly diastereoselectively under substrate control. As for our previous synthesis of racemic salvinorin A, two intramolecular Diels-Alder reactions were applied to generate the tricyclic core. A chemoselective Mitsunobu inversion of a syn 1,2-diol allowed for further streamlining of the original reaction sequence by two steps. Overall, (-)-salvinorin A was synthesized in only 16 steps starting from 3-furaldehyde with 1.4 % total yield. Furthermore, an alternative intramolecular Diels-Alder strategy employing a 2-bromo-1,3-diene moiety was investigated.
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Affiliation(s)
- Patrick Zimdars
- Fakultät Chemie und LebensmittelchemieOrganische Chemie ITechnische Universität DresdenBergstraße 6601069DresdenGermany
| | - Yuzhou Wang
- Fakultät Chemie und LebensmittelchemieOrganische Chemie ITechnische Universität DresdenBergstraße 6601069DresdenGermany
| | - Peter Metz
- Fakultät Chemie und LebensmittelchemieOrganische Chemie ITechnische Universität DresdenBergstraße 6601069DresdenGermany
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2
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A facile lipase-catalyzed KR approach toward enantiomerically enriched homopropargyl alcohols. Bioorg Chem 2019; 93:102754. [DOI: 10.1016/j.bioorg.2019.01.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 11/21/2022]
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3
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Sengoku T, Ikeda I, Ai K, Takahashi M, Yoda H. Indium- and zinc-catalyzed enantioselective amide propargylation of aldehydes with stannylated allenyl amides. Org Biomol Chem 2019; 17:2614-2618. [PMID: 30762059 DOI: 10.1039/c9ob00040b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The catalytic enantioselective propargylation of aldehydes with newly prepared stannyl allenyl amides is described. The reaction has been accomplished by using catalytic amounts of indium chloride, zinc chloride, and a chiral BINOL derivative, affording amide-functionalized homopropargyl alcohols in excellent yields and enantioselectivities.
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Affiliation(s)
- Tetsuya Sengoku
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561, Japan.
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Ambler BR, Woo SK, Krische MJ. Catalytic Enantioselective Carbonyl Propargylation Beyond Preformed Carbanions: Reductive Coupling and Hydrogen Auto-Transfer. ChemCatChem 2019; 11:324-332. [PMID: 31588251 PMCID: PMC6777576 DOI: 10.1002/cctc.201801121] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Indexed: 12/25/2022]
Abstract
Chiral metal complexes catalyze enantioselective carbonyl propargylation via reductive coupling or as hydrogen auto-transfer processes, in which reactant alcohols serve dually as reductant and carbonyl proelectrophile. Unlike classical propargylation protocols, which rely on allenylmetal reagents or metallic reductants (e.g. NHK reactions), reductive protocols for carbonyl propargylation can occur in the absence of stoichiometric metals, precluding generation of metallic byproducts. Propargylations of this type exploit both enyne and propargyl halide pronucleophiles.
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Affiliation(s)
- Brett R. Ambler
- University of Texas at Austin, Department of Chemistry, Welch Hall (A5300), 105 E 24 St., Austin, TX 78712, USA
| | - Sang Kook Woo
- University of Ulsan, Department of Chemistry, 93 Daehak-Ro, Nam-Gu, Ulsan 44610, Korea
| | - Michael J. Krische
- University of Texas at Austin, Department of Chemistry, Welch Hall (A5300), 105 E 24 St., Austin, TX 78712, USA
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Chatterjee PN, Paul D, Sawkmie ML, Sinha AK, Khatua S. Synthesis, characterization of active Sn(0), and its application in selective propargylation of aldehyde at room temperature in water. CAN J CHEM 2019. [DOI: 10.1139/cjc-2017-0745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Active Sn(0) particles are synthesized in high yields by the chemical reduction of the blue–black stannous oxide using freshly prepared sodium stannite solution as reducing agent at 40 °C and 60 °C. The Sn(0) particles are characterized using powder XRD, SEM, and DSC. The as-synthesized Sn(0) particles are applied as reagent for the regioselective synthesis of homopropargyl alcohols from propargyl bromide and aldehydes in distilled water at room temperature (in 50%–84% yields). No assistance of heat, microwave, ultrasound, organic co-solvent, co-reagent, or inert atmosphere is required for this reaction. The propargylation reaction is highly chemoselective towards aldehyde over other less electrophilic carbonyl functional groups such as ketone, amide, and carboxylic acid. Our in-house synthesized homopropargyl alcohols can be used to synthesize conjugated 1,3-diynes.
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Affiliation(s)
- Paresh Nath Chatterjee
- Department of Chemistry, National Institute of Technology Meghalaya, Bijni Complex, Laitumkhrah, Shillong 793003, Meghalaya, India
| | - Dipankar Paul
- Department of Chemistry, National Institute of Technology Meghalaya, Bijni Complex, Laitumkhrah, Shillong 793003, Meghalaya, India
| | - Micky Lanster Sawkmie
- Department of Chemistry, National Institute of Technology Meghalaya, Bijni Complex, Laitumkhrah, Shillong 793003, Meghalaya, India
| | - Arun Kumar Sinha
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, West Bengal, India
| | - Snehadrinarayan Khatua
- Centre for Advance Studies, Department of Chemistry, North Eastern Hill University, Shillong 793022, India
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Asymmetric Addition of Propargylic Silanes to Aldehydes Catalyzed by Chiral Phosphine-Silver Alkoxide Complex. ChemistrySelect 2018. [DOI: 10.1002/slct.201802999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Liang T, Woo SK, Krische MJ. C-Propargylation Overrides O-Propargylation in Reactions of Propargyl Chloride with Primary Alcohols: Rhodium-Catalyzed Transfer Hydrogenation. Angew Chem Int Ed Engl 2016; 55:9207-11. [PMID: 27321353 PMCID: PMC4965293 DOI: 10.1002/anie.201603575] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 05/10/2016] [Indexed: 12/13/2022]
Abstract
The canonical SN 2 behavior displayed by alcohols and activated alkyl halides in basic media (O-alkylation) is superseded by a pathway leading to carbinol C-alkylation under the conditions of rhodium-catalyzed transfer hydrogenation. Racemic and asymmetric propargylations are described.
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Affiliation(s)
- Tao Liang
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA
| | - Sang Kook Woo
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA
| | - Michael J Krische
- University of Texas at Austin, Department of Chemistry, 105 E 24th St. (A5300), Austin, TX, 78712-1167, USA.
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Liang T, Woo SK, Krische MJ. C
‐Propargylation Overrides
O
‐Propargylation in Reactions of Propargyl Chloride with Primary Alcohols: Rhodium‐Catalyzed Transfer Hydrogenation. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201603575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Tao Liang
- University of Texas at AustinDepartment of Chemistry 105 E 24th St. (A5300) Austin TX 78712-1167 USA
| | - Sang Kook Woo
- University of Texas at AustinDepartment of Chemistry 105 E 24th St. (A5300) Austin TX 78712-1167 USA
| | - Michael J. Krische
- University of Texas at AustinDepartment of Chemistry 105 E 24th St. (A5300) Austin TX 78712-1167 USA
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Mahlau M, García-García P, List B. Asymmetric Counteranion-Directed Catalytic Hosomi-Sakurai Reaction. Chemistry 2012. [DOI: 10.1002/chem.201203623] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Peng Z, Takenaka N. Applications of Helical-Chiral Pyridines as Organocatalysts in Asymmetric Synthesis. CHEM REC 2012; 13:28-42. [DOI: 10.1002/tcr.201200010] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Indexed: 11/09/2022]
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11
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Geary LM, Leung JC, Krische MJ. Ruthenium-catalyzed reductive coupling of 1,3-enynes and aldehydes by transfer hydrogenation: anti-diastereoselective carbonyl propargylation. Chemistry 2012; 18:16823-7. [PMID: 23147989 DOI: 10.1002/chem.201202446] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 09/12/2012] [Indexed: 12/25/2022]
Abstract
Under the conditions of ruthenium-catalyzed transfer hydrogenation employing isopropanol as a source of hydrogen, isopropoxy-substituted enyne 1 b and aldehydes 3 a-3 l engage in reductive coupling to provide products of propargylation 4 a-4 l with good to complete levels of anti-diastereoselectivity. The unprotected tertiary hydroxy moiety of isopropoxy enyne 1 b is required to enforce diastereoselectivity. Deuterium-labeling studies corroborate reversible enyne hydrometalation in advance of carbonyl addition. As demonstrated in the conversion of 4 f-h and 4 k to 5 f-h and 5 k, the isopropoxy group of the product is readily cleaved upon exposure to aqueous sodium hydroxide to reveal the terminal alkyne.
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Affiliation(s)
- Laina M Geary
- Department of Chemistry & Biochemistry, The University of Texas at Austin, 78712-1167, USA
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12
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Woo SK, Geary LM, Krische MJ. Enantioselective Carbonyl Propargylation by Iridium-Catalyzed Transfer Hydrogenative Coupling of Alcohols and Propargyl Chlorides. Angew Chem Int Ed Engl 2012; 51:7830-4. [DOI: 10.1002/anie.201203334] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Indexed: 11/05/2022]
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13
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Woo SK, Geary LM, Krische MJ. Enantioselective Carbonyl Propargylation by Iridium-Catalyzed Transfer Hydrogenative Coupling of Alcohols and Propargyl Chlorides. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201203334] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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14
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Abstract
This paper describes the chiral synthesis of R-2,6-dimethyl-4-(3-nitro phenyl)-1,4- dihydro-pyridine-3,5-dicarboxylic acid 3-ethyl ester 5-methyl ester (R-Nitrendipine) using chiral phase transfer catalyst. The structure of the obtained nitrendipine crystals was determined with single crystal X-ray diffraction. The crystal is monoclinic, with the space group of P21/c and unit cell constants of a=8.8577(15), b=15.581(3), c=12.999(2)Å, β=92.458(4)°, V=1792.3(5)Å3, Z=4, Dc =1.335g/cm3, F(000)=760. X-ray analysis reveals that the product is a chiral nitrendipine with R-configuration of the dihydropyridine ring. And measurement of polarimeter reveals that the synthesized nitrendipine is a chiral molecular.
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Geary LM, Woo SK, Leung JC, Krische MJ. Diastereo- and Enantioselective Iridium-Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3-Enynes as Allenylmetal Equivalents. Angew Chem Int Ed Engl 2012; 51:2972-6. [DOI: 10.1002/anie.201200239] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Indexed: 11/09/2022]
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16
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Geary LM, Woo SK, Leung JC, Krische MJ. Diastereo- and Enantioselective Iridium-Catalyzed Carbonyl Propargylation from the Alcohol or Aldehyde Oxidation Level: 1,3-Enynes as Allenylmetal Equivalents. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200239] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Haddad TD, Hirayama LC, Buckley JJ, Singaram B. Indium-Mediated Asymmetric Barbier-Type Propargylations: Additions to Aldehydes and Ketones and Mechanistic Investigation of the Organoindium Reagents. J Org Chem 2012; 77:889-98. [DOI: 10.1021/jo201980b] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Terra D. Haddad
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street,
Santa Cruz, California 95064, United States
| | - Lacie C. Hirayama
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street,
Santa Cruz, California 95064, United States
| | - Jannise J. Buckley
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street,
Santa Cruz, California 95064, United States
| | - Bakthan Singaram
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, 1156 High Street,
Santa Cruz, California 95064, United States
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Hassan A, Townsend IA, Krische MJ. Catalytic enantioselective Grignard Nozaki-Hiyama methallylation from the alcohol oxidation level: chloride compensates for π-complex instability. Chem Commun (Camb) 2011; 47:10028-30. [PMID: 21829853 DOI: 10.1039/c1cc14392a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Methallyl chloride serves as an efficient allyl donor in highly enantioselective Grignard Nozaki-Hiyama methallylations from the alcohol or aldehyde oxidation level via iridium catalyzed transfer hydrogenation. Under identical conditions, methallyl acetate does not react efficiently. Double methallylation of 1,3-propanediol provides the C(2)-symmetric adduct as a single enantiomer, as determined by HPLC analysis.
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Affiliation(s)
- Abbas Hassan
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, TX 78712, USA
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Barnett DS, Schaus SE. Asymmetric propargylation of ketones using allenylboronates catalyzed by chiral biphenols. Org Lett 2011; 13:4020-3. [PMID: 21732609 PMCID: PMC3155969 DOI: 10.1021/ol201535b] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chiral biphenols catalyze the enantioselective asymmetric propargylation of ketones using allenylboronates. The reaction uses 10 mol % of 3,3'-Br(2)-BINOL as the catalyst and allenyldioxoborolane as the nucleophile, in the absence of solvent, and under microwave irradiation to afford the homopropargylic alcohol. The reaction products are obtained in good yields (60-98%) and high enantiomeric ratios (3:1-99:1). Diastereoselective propargylations using chiral racemic allenylboronates result in good diastereoselectivities (dr >86:14) and enantioselectivities (er >92:8) under the catalytic conditions.
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Affiliation(s)
- David S. Barnett
- Department of Chemistry, Life Science and Engineering Building, Boston University, 24 Cummington Street, Boston, Massachusetts, 02215
| | - Scott E. Schaus
- Department of Chemistry, Life Science and Engineering Building, Boston University, 24 Cummington Street, Boston, Massachusetts, 02215
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Chen J, Captain B, Takenaka N. Helical Chiral 2,2′-Bipyridine N- Monoxides as Catalysts in the Enantioselective Propargylation of Aldehydes with Allenyltrichlorosilane. Org Lett 2011; 13:1654-7. [DOI: 10.1021/ol200102c] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Jinshui Chen
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
| | - Burjor Captain
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
| | - Norito Takenaka
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, United States
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Affiliation(s)
- Chang-Hua Ding
- State Key Laboratory of Organometallic Chemistry, §Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
| | - Xue-Long Hou
- State Key Laboratory of Organometallic Chemistry, §Shanghai-Hong Kong Joint Laboratory in Chemical Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China
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Usanov DL, Yamamoto H. Asymmetric Nozaki-Hiyama Propargylation of Aldehydes: Enhancement of Enantioselectivity by Cobalt Co-Catalysis. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002751] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Usanov DL, Yamamoto H. Asymmetric Nozaki-Hiyama Propargylation of Aldehydes: Enhancement of Enantioselectivity by Cobalt Co-Catalysis. Angew Chem Int Ed Engl 2010; 49:8169-72. [DOI: 10.1002/anie.201002751] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Sezer S, Şahin E, Tanyeli C. Stereoselective synthesis of optically active cyclopenta[c]pyrans and cyclopenta[c]furans by the intramolecular Pauson–Khand reaction. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.tetasy.2010.02.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Maruoka K. Design of Sophisticated Bidentate Lewis Acids and Organocatalysts for Fine Organic Synthesis. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2009. [DOI: 10.1246/bcsj.82.917] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Huang JM, Luo HC, Chen ZX, Yang GC, Loh TP. An In-Mediated Tandem Reaction of Aldehydes with 3-Bromo-1-propyne To Produce 1-Substituted-3-methylene-5-yn-1-ol Compounds. European J Org Chem 2008. [DOI: 10.1002/ejoc.200700758] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Conformational control on remote stereochemistry in the intramolecular Pauson–Khand reactions of enynes tethered to homoallyl and homopropargyl alcohols. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.tetasy.2006.11.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Andrés JM, Pedrosa R, Pérez-Encabo A, Ramírez M. Diastereoselective synthesis of enantioenriched homopropargyl amino alcohols from α-dibenzylamino aldehydes and their use as chiral synthons. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.05.060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Schneider U, Sugiura M, Kobayashi S. Highly Selective Preparation of Allenic and Homopropargylic Hydrazides through Regiospecific Addition of Propargyltrichlorosilane and Allenyltrichlorosilane to Various Types ofN-Acylhydrazones. Adv Synth Catal 2006. [DOI: 10.1002/adsc.200505379] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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31
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Schneider U, Sugiura M, Kobayashi S. Highly selective formation of propargyl- and allenyltrichlorosilanes and their regiospecific addition to various types of aldehydes: preparation of both allenic and homopropargylic alcohols. Tetrahedron 2006. [DOI: 10.1016/j.tet.2005.08.114] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Kim JG, Waltz KM, Garcia IF, Kwiatkowski D, Walsh PJ. Catalytic Asymmetric Allylation of Ketones and a Tandem Asymmetric Allylation/Diastereoselective Epoxidation of Cyclic Enones. J Am Chem Soc 2004; 126:12580-5. [PMID: 15453790 DOI: 10.1021/ja047758t] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A simple procedure is reported for the catalytic asymmetric allylation of ketones, utilizing titanium tetraisopropoxide, BINOL, 2-propanol additive, and tetraallylstannane as allylating agent. A variety of ketone substrates, including acetophenone derivatives and alpha,beta-unsaturated cyclic enones, reacted to form tertiary homoallylic alcohols in good yields (67-99%) and with high levels of enantioselectivity (generally >80%). A novel one-pot enantioselective allylation/diastereoselective epoxidation has also been introduced. Thus, upon completion of the allyl addition to conjugated cyclic enones, 1 equiv of tert-butyl hydroperoxide is added and the directed epoxidation of the allylic double bond ensues to afford the epoxy alcohol with high diastereoselectivity.
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Affiliation(s)
- Jeung Gon Kim
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104-6323, USA
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Abstract
Catalytic asymmetric Nozaki-Hiyama propargylation with ligand 1c proceeds with good to excellent enantioselectivity. Tuning of ligand 1 dramatically changes the enantioselectivity, and we propose models A and B to explain the change and outcome of the enantioselectivity.
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Affiliation(s)
- Masahiro Inoue
- Department of Chemistry, School of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
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