1
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Paparella AN, Stallone M, Pulpito M, Perna FM, Capriati V, Vitale P. An enhanced stereoselective synthesis of α,β-unsaturated esters through the Horner-Wadsworth-Emmons reaction in deep eutectic solvents. Org Biomol Chem 2024; 22:1885-1891. [PMID: 38349132 DOI: 10.1039/d3ob02083e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
A new scalable synthesis of (E)-α,β-unsaturated esters has been developed using protic, non-toxic, and biodegradable deep eutectic solvents through the Horner-Wadsworth-Emmons reaction between triethyl phosphonates and (hetero)aromatic carbonyl compounds, encompassing electron-withdrawing and electron-donating groups. Stereoselective preparation of disubstituted or trisubstituted ethyl cinnamate derivatives is achieved in the presence of LiOH, K2CO3, or DBU as bases, at room temperature and under air. Demonstrated with the synthesis of (E)-ethyl 3-(4-bromophenyl)acrylate, the same eutectic mixture (choline chloride/urea) proved to be reusable for three consecutive runs. Gram-scale reactions (10 mmol) can be carried out without the formation of side products, thereby ensuring high atom economy and an EcoScale score of 71.
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Affiliation(s)
- Andrea Nicola Paparella
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
| | - Margherita Stallone
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
| | - Mara Pulpito
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
| | - Filippo Maria Perna
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
| | - Vito Capriati
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
| | - Paola Vitale
- Dipartimento di Farmacia-Scienze del Farmaco, Università di Bari "Aldo Moro", Consorzio C.I.N.M.P.I.S., Via E. Orabona, 4, 70125 Bari, Italy.
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2
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Volchkov I, Powell BV, Zatolochnaya OV, Leung JC, Pennino S, Wu L, Gonnella NC, Bhaskararao B, Kozlowski MC, Reeves JT. Practical Synthesis of Terminal Vinyl Fluorides. J Org Chem 2023; 88:10881-10904. [PMID: 37441763 PMCID: PMC10530197 DOI: 10.1021/acs.joc.3c00917] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/15/2023]
Abstract
The synthesis of di- and trisubstituted vinyl fluorides with high isomeric purity remains a challenge for organic synthesis. While many methods exist to access these compounds, the separation of the desired isomer from the minor isomer and/or starting materials often is difficult. Herein, we report a practical method to access di- and trisubstituted vinyl fluorides via a selective Horner-Wadsworth-Emmons olefination/hydrolysis, which provides crystalline 2-fluoroacrylic acids in high (>98%) E-isomeric purity. A subsequent silver-catalyzed stereoretentive decarboxylation provides the title substances with high isomeric purity and without the need for tedious chromatography to remove the minor isomer. The process was amenable to a variety of aldehydes and ketones and provided a diverse array of di- and trisubstituted vinyl fluorides. The sequence was applied to the synthesis of antibacterial and anti-inflammatory compounds.
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Affiliation(s)
- Ivan Volchkov
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Brent V. Powell
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Olga V. Zatolochnaya
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Joyce C. Leung
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Scott Pennino
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Lifen Wu
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Nina C. Gonnella
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
| | - Bangaru Bhaskararao
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Marisa C. Kozlowski
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Jonathan T. Reeves
- Departments of Chemical Development and Material and Analytical Sciences, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, Connecticut 06877, United States
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3
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Paulin EK, Leung E, Pilkington LI, Barker D. Synthesis and Anti-Proliferative Evaluation of Arctigenin Analogues with C-9' Derivatisation. Int J Mol Sci 2023; 24:ijms24021167. [PMID: 36674683 PMCID: PMC9866048 DOI: 10.3390/ijms24021167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 12/22/2022] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Dibenzylbutyrolactone lignans (DBLs) are a class of natural products with a wide variety of biological activities. Due to their potential for the development of human therapeutic agents, DBLs have been subjected to various SAR studies in order to optimise activity. Previous reports have mainly considered changes on the aromatic rings and at the benzylic carbons of the compounds, whilst the effects of substituents in the lactone, at the C-9' position, have been relatively unexplored. This position has an unexploited potential for the development of novel dibenzyl butyrolactone derivatives, with previous preliminary findings revealing C-9'-hydroxymethyl analogues inducing programmed cell cycle death. Using the core structure of the bioactive natural product arctigenin, C-9' derivatives were synthesised using various synthetic pathways and with prepared derivatives providing more potent anti-proliferative activity than the C-9'-hydroxymethyl lead compound.
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Affiliation(s)
- Emily K. Paulin
- School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
| | - Euphemia Leung
- Auckland Cancer Society Research Centre, University of Auckland, Auckland 1023, New Zealand
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland 1023, New Zealand
| | - Lisa I. Pilkington
- School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - David Barker
- School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6012, New Zealand
- Correspondence: ; Tel.: +64-9-373-7599
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4
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Janicki I, Kiełbasiński P. Highly Z-Selective Horner-Wadsworth-Emmons Olefination Using Modified Still-Gennari-Type Reagents. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27207138. [PMID: 36296731 PMCID: PMC9609750 DOI: 10.3390/molecules27207138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/18/2022] [Accepted: 10/18/2022] [Indexed: 11/07/2022]
Abstract
In this report, new, easily accessible reagents for highly Z-selective HWE reactions are presented. Alkyl di-(1,1,1,3,3,3-hexafluoroisopropyl)phosphonoacetates, structurally similar to Still–Gennari type reagents, were tested in HWE reactions with a series of various aldehydes. Very good Z-selectivity (up to a 98:2 Z:E ratio) was achieved in most cases along with high yields. Application of the new reagents may be a valuable, practical alternative to the well-established Still–Gennari or Ando Z-selective carbonyl group olefination protocols.
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5
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Samineni R, Eda V, Rao P, Sen S, Oruganti S. Grignard Reagents as Niche Bases in the Synthesis of Pharmaceutically Relevant Molecules. ChemistrySelect 2022. [DOI: 10.1002/slct.202102853] [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)
- Ramesh Samineni
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS) Dr. Reddy's Institute of Life Sciences University of Hyderabad campus, Gachibowli Hyderabad 500046 India
| | - Vishnuvardhana Eda
- Center for Process Research and Innovation (CPRI) Dr. Reddy's Institute of Life Sciences University of Hyderabad campus, Gachibowli Hyderabad 500046 India
| | - Pallavi Rao
- Center for Process Research and Innovation (CPRI) Dr. Reddy's Institute of Life Sciences University of Hyderabad campus, Gachibowli Hyderabad 500046 India
| | - Saikat Sen
- Center for Process Research and Innovation (CPRI) Dr. Reddy's Institute of Life Sciences University of Hyderabad campus, Gachibowli Hyderabad 500046 India
| | - Srinivas Oruganti
- Center for Process Research and Innovation (CPRI) Dr. Reddy's Institute of Life Sciences University of Hyderabad campus, Gachibowli Hyderabad 500046 India
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6
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Souto JA, Román D, Domínguez M, Lera ÁR. Synthetic Studies on Alotamide A: Construction of
N
‐Demethylalotamide A. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101104] [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)
- José A. Souto
- CINBIO Universidade de Vigo Departamento de Química Orgánica 36310 Vigo España
| | - David Román
- CINBIO Universidade de Vigo Departamento de Química Orgánica 36310 Vigo España
| | - Marta Domínguez
- CINBIO Universidade de Vigo Departamento de Química Orgánica 36310 Vigo España
| | - Ángel R. Lera
- CINBIO Universidade de Vigo Departamento de Química Orgánica 36310 Vigo España
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7
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δ-Lactones-A New Class of Compounds That Are Toxic to E. coli K12 and R2-R4 Strains. MATERIALS 2021; 14:ma14112956. [PMID: 34070884 PMCID: PMC8199173 DOI: 10.3390/ma14112956] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/14/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022]
Abstract
Lactones are among the well-known organic substances with a specific taste and smell. They are characterized by antibacterial, antiviral, anti-inflammatory, and anti-cancer properties. In recent years, among this group of compounds, new biologically active substances have been searched by modifying the main (leading) structure with new analogs with stronger or different responses that may have a toxic effect on the cells of pathogenic bacteria and constitute an alternative to commonly used antibiotics. A preliminary study of δ-lactone derivatives as new potential candidates for antibacterial drugs was conducted. Particular emphasis was placed on the selection of the structure of lactones with the highest biological activity, especially those with fluorine in their structure as a substituent in terms of action on bacterial lipopolysaccharide (LPS) in the model strains of Escherichia coli K12 (without LPS in its structure) and R2–R4 (LPS of different lengths in its structure). In the presented studies, on the basis of the conducted MIC and MBC tests, it was shown that the antibacterial (toxic) activity of lactones depends on their structure and the length of the bacterial LPS in the membrane of specific strains. Moreover, oxidative damage of bacterial DNA isolated from bacteria after modification with newly synthesized compounds after application of the repair enzyme Fpg glycosylase was analyzed. The analyzed damage values were compared with the modification with appropriate antibiotics: ciprofloxacin, bleomycin, and cloxacillin. The presented research clearly shows that lactone derivatives can be potential candidates as substitutes for drugs, e.g., the analyzed antibiotics. Their chemical and biological activity is related to coumarin derivatives and the corresponding δ-lactone groups in the structure of the substituent. The observed results are of particular importance in the case of increasing bacterial resistance to various drugs and antibiotics, especially in nosocomial infections and neoplasms, and in the era of a microbial pandemic.
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8
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Da Silva Pinto S, Davies SG, Fletcher AM, Newton SK, Roberts PM, Thomson JE. Short asymmetric syntheses of sphinganine [(2S,3R)-2-aminooctadecane-1,3-diol] and its C(2)-epimer. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2020.152743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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9
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Casey KC, Brown AM, Robinson JR. Yttrium and lanthanum bis(phosphine-oxide)methanides: structurally diverse, dynamic, and reactive. Inorg Chem Front 2021. [DOI: 10.1039/d0qi01438a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Homoleptic yttrium and lanthanum complexes of bis(phosphineoxide) methanides, RE(HPhL)3 and RE2(HMeL)6, promote the first rare-earth mediated Horner-Wittig and acid-base chemistry consistent with multifunctional reactivity (Lewis-acid/Brønstedbase).
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10
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Hédou D, Voisin‐Chiret AS. Br vs. TsO Chemoselective Suzuki–Miyaura Cross‐Coupling Reaction on Nicotinaldehyde Moiety for the Preparation of 2,3,5‐Trisubstituted Pyridines. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000417] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Damien Hédou
- EA 4258, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie) ‐ FR CNRS INC3M Normandie Université, UNICAEN Boulevard Becquerel 14032 Caen France
| | - Anne Sophie Voisin‐Chiret
- EA 4258, CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie) ‐ FR CNRS INC3M Normandie Université, UNICAEN Boulevard Becquerel 14032 Caen France
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11
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Chai Y, Zhou J, Wu Y, Feng Y, Wang P, Chen Y, Wang X, Zhao B, Zhang Q. Organo-Catalyzed Regio- and Geometry-Specific Construction of β-Hydroxyl-α-vinyl Carboxylic Esters: Substrate Scope, Mechanistic Insights, and Applications. J Org Chem 2018; 83:10476-10486. [PMID: 30088930 DOI: 10.1021/acs.joc.8b01510] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A green protocol has been developed for the synthesis of β-hydroxyl-α-vinyl carboxylic esters using aldehydes and α,β-unsaturated esters bearing an activated γ proton as starting materials under Morita-Baylis-Hillman (MBH) reaction conditions. Diverse β-hydroxyl-α-vinyl carboxylic esters have been synthesized regiospecifically in moderate to good yields with only E geometric selectivity. Other remarkable features include atom efficiency, environmental benignancy, and mild reaction conditions. Furthermore, the reaction products could be readily converted into tetrahydrofuran, dihydrofuran, and furan derivatives.
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Affiliation(s)
- Yonghai Chai
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - JinJin Zhou
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Yanbin Wu
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Yingle Feng
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Panru Wang
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Yange Chen
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Xinying Wang
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Beibei Zhao
- Key Laboratory of Applied Surface and Colloid Chemistry, MOE , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
| | - Qi Zhang
- School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an , Shaanxi 710119 , P.R. China
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12
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Davies SG, Fletcher AM, Greenaway CJ, Kennedy MS, Mayer C, Roberts PM, Thomson JE. Trading N and O. Part 4: Asymmetric synthesis of syn-β-substituted-α-amino acids. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.04.071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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13
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Tomberg A, Kundu S, Zhou F, Li CJ, Moitessier N. Revised Mechanism for a Ruthenium-Catalyzed Coupling of Aldehyde and Terminal Alkyne. ACS OMEGA 2018; 3:3218-3227. [PMID: 31458579 PMCID: PMC6641445 DOI: 10.1021/acsomega.7b01877] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 02/28/2018] [Indexed: 06/10/2023]
Abstract
Ruthenium catalysts have been found to be of great use for many kinds of reactions. Understanding the details of the catalytic cycle allows to not only rationalize experimental results but also to improve upon reactions. Herein, we present a detailed computational study of a ruthenium-catalyzed coupling between a terminal alkyne and an aldehyde. The reaction under examination facilitates novel access to olefins with the concurrent loss of a single carbon as carbon monoxide. The reaction was first developed in 2009, but the tentative mechanism initially proposed was proven to be contradictory to some experimental data obtained since then. Using a combination of computational investigations and isotope-labeling experiments, several potential mechanisms have been studied. In contrast to the [2+2] cycloaddition mechanism suggested for similar catalysts, we propose a new consensus pathway that proceeds through the formation of a ruthenium-vinylidene complex that undergoes an aldol-type reaction with the aldehyde to yield the product olefins. Computational insights into the influence of different reagents used to optimize reaction conditions and the intricacies of decarbonylation of a Ru-CO complex affecting catalyst turnover are highlighted.
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14
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Davies SG, Fletcher AM, Roberts PM, Thomson JE. The conjugate addition of enantiomerically pure lithium amides as chiral ammonia equivalents part III: 2012–2017. ACTA ACUST UNITED AC 2017. [DOI: 10.1016/j.tetasy.2017.10.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Plutschack MB, Pieber B, Gilmore K, Seeberger PH. The Hitchhiker's Guide to Flow Chemistry ∥. Chem Rev 2017; 117:11796-11893. [PMID: 28570059 DOI: 10.1021/acs.chemrev.7b00183] [Citation(s) in RCA: 1020] [Impact Index Per Article: 145.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Flow chemistry involves the use of channels or tubing to conduct a reaction in a continuous stream rather than in a flask. Flow equipment provides chemists with unique control over reaction parameters enhancing reactivity or in some cases enabling new reactions. This relatively young technology has received a remarkable amount of attention in the past decade with many reports on what can be done in flow. Until recently, however, the question, "Should we do this in flow?" has merely been an afterthought. This review introduces readers to the basic principles and fundamentals of flow chemistry and critically discusses recent flow chemistry accounts.
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Affiliation(s)
- Matthew B Plutschack
- Department of Biomolecular Systems, Max-Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Bartholomäus Pieber
- Department of Biomolecular Systems, Max-Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Kerry Gilmore
- Department of Biomolecular Systems, Max-Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Peter H Seeberger
- Department of Biomolecular Systems, Max-Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany.,Institute of Chemistry and Biochemistry, Department of Biology, Chemistry and Pharmacy, Freie Universität Berlin , Arnimallee 22, 14195 Berlin, Germany
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16
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Brambilla M, Davies SG, Fletcher AM, Roberts PM, Thomson JE, Zimmer D. Pyrrolizidines, indolizidines and quinolizidines via a double reductive cyclisation protocol: concise asymmetric syntheses of (+)-trachelanthamidine, (+)-tashiromine and (+)-epilupinine. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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17
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Buchman M, Csatayová K, Davies SG, Fletcher AM, Houlsby ITT, Roberts PM, Rowe SM, Thomson JE. Asymmetric Syntheses of (+)-Preussin B, the C(2)-Epimer of (−)-Preussin B, and 3-Deoxy-(+)-preussin B. J Org Chem 2016; 81:4907-22. [DOI: 10.1021/acs.joc.6b00362] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marek Buchman
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Kristína Csatayová
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Stephen G. Davies
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Ai M. Fletcher
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Ian T. T. Houlsby
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Paul M. Roberts
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - Sam M. Rowe
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
| | - James E. Thomson
- Department
of Chemistry,
Chemistry Research Laboratory, University of Oxford, Mansfield
Road, Oxford OX1 3TA, U.K
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18
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Davies SG, Fletcher AM, Frost AB, Kennedy MS, Roberts PM, Thomson JE. Trading N and O. Part 3: Synthesis of 1,2,3,4-tetrahydroisoquinolines from α-hydroxy-β-amino esters. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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19
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Larsen BJ, Sun Z, Lachacz E, Khomutnyk Y, Soellner MB, Nagorny P. Synthesis and Biological Evaluation of Lactimidomycin and Its Analogues. Chemistry 2015; 21:19159-67. [PMID: 26577990 DOI: 10.1002/chem.201503527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Indexed: 02/06/2023]
Abstract
The studies culminating in the total synthesis of the glutarimide-containing eukaryote translation elongation inhibitor lactimidomycin are described. The optimized synthetic route features a Zn(II)-mediated intramolecular Horner-Wadsworth-Emmons (HWE) reaction resulting in a highly stereoselective formation of the strained 12-membered macrolactone of lactimidomycin on a 423 mg scale. The presence of the E,Z-diene functionality was found to be key for effective macrocyclizations as a complete removal of these unsaturation units resulted in exclusive formation of the dimer rather than monocyclic enoate. The synthetic route features a late-stage installation of the glutarimide functionality via an asymmetric catalytic Mukaiyama aldol reaction, which allows for a quick generation of lactimidomycin homolog 55 containing two additional carbons in the glutarimide side chain. Similar to lactimidomycin, this analog was found to possess cytotoxicity against MDA-MB-231 breast cancer cells (GI50 =1-3 μM) using in vitro 2D and 3D assays. Although lactimidomycin was found to be the most potent compound in terms of anticancer activity, 55 as well as truncated analogues 50-52 lacking the glutarimide side-chain were found to be significantly less toxic against human mammary epithelial cells.
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Affiliation(s)
- Brian J Larsen
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Zhankui Sun
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Eric Lachacz
- Medicinal Chemistry Department, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065 (USA)
| | - Yaroslav Khomutnyk
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA)
| | - Matthew B Soellner
- Medicinal Chemistry Department, College of Pharmacy, University of Michigan, 428 Church Street, Ann Arbor, MI 48109-1065 (USA).
| | - Pavel Nagorny
- Department of Chemistry, University of Michigan, 930 N. University Avenue, Ann Arbor, MI 48109-1055 (USA).
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21
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Hoffmann M, Deshmukh S, Werner T. Scope and Limitation of the Microwave-Assisted Catalytic Wittig Reaction. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500310] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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22
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Davies SG, Thomson JE. The homalium alkaloids: isolation, synthesis, and absolute configuration assignment. THE ALKALOIDS. CHEMISTRY AND BIOLOGY 2015; 74:121-58. [PMID: 25845060 DOI: 10.1016/bs.alkal.2014.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The structurally related natural products (-)-homaline, (-)-hopromine, (-)-hoprominol, and (-)-hopromalinol have been collectively termed the homalium alkaloids. All four alkaloids possess bis-ζ-azalactam structures, but differ only by the identities of the side chain on each lactam ring. Since their isolation (from the leaves of Homalium pronyense Guillaum found in the forests of New Caledonia), there have been several syntheses of homaline, hopromine, hoprominol, and hopromalinol in both racemic and enantiopure forms. The most highly yielding and versatile strategy for their synthesis employs the conjugate addition of an enantiopure lithium amide reagent to an α,β-unsaturated ester as the key stereodefining step. This methodology has been used in the syntheses of all four members of the homalium alkaloid family and their stereoisomers.
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Lauer MG, Thompson MK, Shaughnessy KH. Controlling olefin isomerization in the heck reaction with neopentyl phosphine ligands. J Org Chem 2014; 79:10837-48. [PMID: 25333873 DOI: 10.1021/jo501840u] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The use of neopentyl phosphine ligands was examined in the coupling of aryl bromides with alkenes. Di-tert-butylneopentylphosphine (DTBNpP) was found to promote Heck couplings with aryl bromides at ambient temperature. In the Heck coupling of cyclic alkenes, the degree of alkene isomerization was found to be controlled by the choice of ligand with DTBNpP promoting isomerization to a much greater extent than trineopentylphosphine (TNpP). Under optimal conditions, DTBNpP provides high selectivity for 2-aryl-2,3-dihydrofuran in the arylation of 2,3-dihydrofuran, whereas TNpP provided high selectivity for the isomeric 2-aryl-2,5-dihydrofuran. A similar complementary product selectivity is seen in the Heck coupling of cyclopentene. Heck coupling of 2-bromophenols or 2-bromoanilides with 2,3-dihydrofurans affords 2,5-epoxybenzoxepin and 2,5-epoxybenzazepins, respectively.
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Affiliation(s)
- Matthew G Lauer
- Department of Chemistry, The University of Alabama , P.O. Box 870336, Tuscaloosa, Alabama 35487-0336, United States
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Davies SG, Fletcher AM, Frost AB, Roberts PM, Thomson JE. Trading N and O. Part 2: Exploiting aziridinium intermediates for the synthesis of β-hydroxy-α-amino acids. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.06.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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The effect of resveratrol and its methylthio-derivatives on the Nrf2-ARE pathway in mouse epidermis and HaCaT keratinocytes. Cell Mol Biol Lett 2014; 19:500-16. [PMID: 25169438 PMCID: PMC6276002 DOI: 10.2478/s11658-014-0209-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 08/22/2014] [Indexed: 12/30/2022] Open
Abstract
Resveratrol is the most extensively studied stilbene derivative. We previously showed that methylthiostilbenes were more effective inhibitors of CYP1A1 and 1B1 activity than resveratrol. In this study, we investigated whether resveratrol and its methylthio-substituted derivatives, i.e. 3-M-4′-MTS (S2), 3,5-DM-4′-MTS (S5) and 3,4,5-TM-4′-MTS (S7) could activate Nrf2 signaling in the mouse epidermis and in human keratinocytes. Western blot analysis showed translocation of Nrf2 from the cytosol to the nucleus in both models. All of the tested stilbenes increased GST activity, but resveratrol was the most effective inducer. Moreover, only resveratrol increased the protein level of GSTP in the mouse epidermis. GSTM was enhanced in HaCaT cells after the treatment with derivatives S2 and S5. The same effect was observed for GSTP in the case of compound S2. Resveratrol and its derivatives reduced the NQO2 protein level in HaCaT cells. Thus, it is possible that increased expression of GSTP or GSTM and GST activity was linked with NQO2 inhibition in these cells. The results of this study indicate that resveratrol and its methylthioderivatives activate Nrf2 not only in the mouse epidermis, but also in human keratinocytes. Upregulating GST isozymes might be particularly important for deactivating chemical carcinogens, such as PAH.
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Moskalenko AI, Boev VI. Development of general methods for the synthesis of new substituted allyl bromides as promising alkenylating agents. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2014. [DOI: 10.1134/s1070428014070069] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Davies SG, Foster EM, Lee JA, Roberts PM, Thomson JE. Doubly diastereoselective conjugate additions of the antipodes of lithium N-benzyl-N-(α-methylbenzyl)amide to enantiopure ε-O-protected α,β-unsaturated esters derived from d-ribose. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.tetasy.2014.02.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Bach T, A. Fort D, J. Woltering T, M. Alker A. Photochemical Reactions of Prop-2-enyl and Prop-2-ynyl Substituted 4-Aminomethyl- and 4-Oxymethyl-2(5H)-furanones. HETEROCYCLES 2014. [DOI: 10.3987/com-13-s(s)67] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Davies SG, Fletcher AM, Frost AB, Lee JA, Roberts PM, Thomson JE. Trading N and O: asymmetric syntheses of β-hydroxy-α-amino acids via α-hydroxy-β-amino esters. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.08.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Samala R, Patro B, Basu MK, Kameswara Rao N, Mukkanti K. Facile total synthesis of gymnoconjugatin A and B. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.04.110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Larsen BJ, Sun Z, Nagorny P. Synthesis of Eukaryotic Translation Elongation Inhibitor Lactimidomycin via Zn(II)-Mediated Horner–Wadsworth–Emmons Macrocyclization. Org Lett 2013; 15:2998-3001. [DOI: 10.1021/ol401186f] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brian J. Larsen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Zhankui Sun
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Pavel Nagorny
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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Willand-Charnley R, Dussault PH. Tandem application of C-C bond-forming reactions with reductive ozonolysis. J Org Chem 2013; 78:42-7. [PMID: 22994627 PMCID: PMC3537893 DOI: 10.1021/jo3015775] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several variants of reductive ozonolysis, defined here as the in situ generation of aldehydes or ketones during ozonolytic cleavage of alkenes, are demonstrated to work effectively in tandem with a number of C-C bond-forming reactions. For reactions involving basic nucleophiles (1,2-addition of Grignard reagents, Wittig or Horner-Emmons olefinations, and directed aldol reactions of lithium enolates), the one-pot process offers a rapid and high-yielding alternative to traditional two-step protocols.
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Affiliation(s)
| | - Patrick H. Dussault
- Department of Chemistry, University of Nebraska–Lincoln, Lincoln, NE 68588-0304
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Brock EA, Davies SG, Lee JA, Roberts PM, Thomson JE. Polyhydroxylated pyrrolizidine alkaloids from transannular iodoaminations: application to the asymmetric syntheses of (−)-hyacinthacine A1, (−)-7a-epi-hyacinthacine A1, (−)-hyacinthacine A2, and (−)-1-epi-alexine. Org Biomol Chem 2013; 11:3187-202. [DOI: 10.1039/c3ob40205c] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Siddiqui ZN, Khan T. P2O5/SiO2 as an efficient heterogeneous catalyst for the synthesis of heterocyclic alkene derivatives under thermal solvent-free conditions. Catal Sci Technol 2013. [DOI: 10.1039/c3cy00095h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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36
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Davies SG, Lee JA, Roberts PM, Stonehouse JP, Thomson JE. Absolute Configuration Assignment by Asymmetric Syntheses of the Homalium Alkaloids (−)-(R,R,R)-Hoprominol and (−)-(4′S,4″R,2‴R)-Hopromalinol. J Org Chem 2012; 77:9724-37. [DOI: 10.1021/jo301830j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Stephen G. Davies
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - James A. Lee
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Paul M. Roberts
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Jeffrey P. Stonehouse
- Novartis Institutes for Biomedical Research, Horsham, West Sussex RH12 5AB,
United Kingdom
| | - James E. Thomson
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
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Davies SG, Lee JA, Roberts PM, Stonehouse JP, Thomson JE. Asymmetric Syntheses of the Homalium Alkaloids (−)-(S,S)-Homaline and (−)-(R,R)-Hopromine. J Org Chem 2012; 77:7028-45. [DOI: 10.1021/jo3012732] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephen G. Davies
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - James A. Lee
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Paul M. Roberts
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | | | - James E. Thomson
- Department
of Chemistry, Chemistry
Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
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Brock EA, Davies SG, Lee JA, Roberts PM, Thomson JE. Asymmetric Synthesis of the Tropane Alkaloid (+)-Pseudococaine via Ring-Closing Iodoamination. Org Lett 2012; 14:4278-81. [DOI: 10.1021/ol3020607] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- E. Anne Brock
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Stephen G. Davies
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - James A. Lee
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - Paul M. Roberts
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
| | - James E. Thomson
- Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, U.K
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39
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The conjugate addition of enantiomerically pure lithium amides as chiral ammonia equivalents part II: 2005−2011. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.tetasy.2012.08.009] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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40
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Convenient strategy for the synthesis of highly functionalizable hydroxylated unsaturated azepanes. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.06.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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41
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Davies SG, Fletcher AM, Lv L, Roberts PM, Thomson JE. Asymmetric synthesis of (−)-(R)-sitagliptin. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.04.025] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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42
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Webb D, Jamison TF. A Continuous Homologation of Esters: An Efficient Telescoped Reduction–Olefination Sequence. Org Lett 2012; 14:2465-7. [DOI: 10.1021/ol300722e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Damien Webb
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Timothy F. Jamison
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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García Ruano JL, Fernández-Salas JA, Maestro MC. Stereocontrolled Fluorobenzylation of Vinyl Sulfones and α,β-Unsaturated Esters Mediated by a Remote Sulfinyl Group. Synthesis of Functionalized Enantiomerically Pure Benzylic Fluorides. J Org Chem 2012; 77:2893-900. [DOI: 10.1021/jo300174k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- José Luis García Ruano
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco,
28049 Madrid, Spain
| | | | - M. Carmen Maestro
- Departamento de Química Orgánica, Universidad Autónoma de Madrid, Cantoblanco,
28049 Madrid, Spain
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Gu Y, Tian SK. Olefination Reactions of Phosphorus-Stabilized Carbon Nucleophiles. Top Curr Chem (Cham) 2012; 327:197-238. [DOI: 10.1007/128_2012_314] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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45
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Davies SG, Foster EM, Frost AB, Lee JA, Roberts PM, Thomson JE. On the origins of diastereoselectivity in the conjugate additions of the antipodes of lithium N-benzyl-(N-α-methylbenzyl)amide to enantiopure cis- and trans-dioxolane containing α,β-unsaturated esters. Org Biomol Chem 2012; 10:6186-200. [DOI: 10.1039/c2ob25099c] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Mali SM, Bandyopadhyay A, Jadhav SV, Kumar MG, Gopi HN. Synthesis of α, β-unsaturated γ-amino esters with unprecedented high (E)-stereoselectivity and their conformational analysis in peptides. Org Biomol Chem 2011; 9:6566-74. [PMID: 21826295 DOI: 10.1039/c1ob05732d] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mild, efficient and racemization-free synthesis of N-protected α, β-unsaturated γ-amino esters with unprecedented high E- stereoselectivity is described. This method is found to be compatible with Boc-, Fmoc- and other side chain protecting groups. The crystal conformations of the vinylogous γ-amino esters in monomers and in homo- and mixed dipeptides are studied. Further, the vinylogous homo-dipeptide showed a β-sheet conformation, while mixed α- and α,β-unsaturated γ-hybrid dipeptide adapted an irregular structure in single crystals.
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Affiliation(s)
- Sachitanand M Mali
- Department of Chemistry Indian Institute of Science Education and Research, Garware Circle Pashan, Pune, Maharashtra 411021, India
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Davies SG, Foster EM, McIntosh CR, Roberts PM, Rosser TE, Smith AD, Thomson JE. Asymmetric synthesis of syn- and anti-α-deuterio-β3-phenylalanine derivatives. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.tetasy.2011.06.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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48
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Chintareddy VR, Ellern A, Verkade JG. P[N(i-Bu)CH(2)CH(2)](3)N: nonionic Lewis base for promoting the room-temperature synthesis of α,β-unsaturated esters, fluorides, ketones, and nitriles using Wadsworth-Emmons phosphonates. J Org Chem 2011; 75:7166-74. [PMID: 20945858 DOI: 10.1021/jo1012515] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The bicyclic triaminophosphine P(RNCH(2)CH(2))(3)N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated. We were able to isolate and characterize (by X-ray means; see above) the reactive WE intermediate species formed from 2b and 1c.
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Alkylation and aldol reactions of acyl derivatives of N-1-(1′-naphthyl)ethyl-O-tert-butylhydroxylamine: asymmetric synthesis of α-alkoxy-, α-substituted-β-alkoxy- and α,β-dialkoxyaldehydes. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.03.105] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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50
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Davies SG, Fletcher AM, Roberts PM, Smith AD. Asymmetric synthesis of Sedum alkaloids via lithium amide conjugate addition. Tetrahedron 2009. [DOI: 10.1016/j.tet.2009.09.104] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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