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Dusso D, Ramirez C, Parise A, Lanza P, Vera DM, Chesta C, Moyano EL, Akhmedov NG. Synthesis of new cyano-substituted analogues of Tröger's bases from bromo-derivatives. A stereochemical dependence of long-range ( n J HH , n = 4, 5, and 6) proton-proton and proton-carbon ( n J CH , n = 1, 2, 3, 4, and 5) coupling constants of these compounds. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2019; 57:423-454. [PMID: 30937941 DOI: 10.1002/mrc.4872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/21/2019] [Accepted: 03/25/2019] [Indexed: 06/09/2023]
Abstract
A free-catalyst microwave-assisted cyanation of brominated Tröger's base derivatives (2a-f) is reported. The procedure is simple, efficient, and clean affording the nitrile compounds (3a-e, I) in very good yields. Complete assignment of 1 H and 13 C chemical shifts of 2a-f, I and 3a-d, I was achieved using gradient selected 1D nuclear magnetic resonance (NMR) techniques (1D zTOCSY, PSYCHE, DPFGSE NOE, and DEPT), homonuclear 2D NMR techniques (gCOSY and zTOCSY), and heteronuclear 2D NMR techniques (gHSQCAD/or pure-shift gHSQCAD, gHMBCAD, bsHSQCNOESY, and gHSQCAD-TOCSY) with adiabatic pulses. Determination of the long-range proton-proton coupling constants n JHH (n = 4, 5, 6) was accomplished by simultaneous irradiation of two protons at appropriate power levels. In turn, determined coupling constants were tested by an iterative simulation program by calculating the 1 H NMR spectrum and comparing it to the experimental spectrum. The excitation-sculptured indirect-detection experiment (EXSIDE) and 1 H-15 N CIGARAD-HMBC (constant time inverse-detection gradient accordion rescaled heteronuclear multiple bond correlation) were applied for determination of long-range carbon-proton coupling constants n JCH (n = 2, 3, and 4) and for assignment of 15 N chemical shift at natural abundance, respectively. DFT/B3LYP optimization studies were performed in order to determine the geometry of 2c using 6-31G(d,p), 6-311G(d,p), and 6-311 + G(d,p) basis sets. For calculation of 1 H and 13 C chemical shifts, n JHH (n = 2, 3, 4, 5, and 6), and n JCH (n = 1, 2, 3, and 4) coupling constants, the GIAO method was employed at the B3LYP/6-31G(d,p), B3LYP/6-31+G(d,p), B3LYP/6-311+G(d,p), B3LYP/6-311++G(2d,2p), B3LYP/cc-pVTZ), and B3LYP/aug-cc-pVTZ) levels of theory. For the first time, a stereochemical dependence magnitude of the long-range n JHH (n = 4, 5, and 6) and n JCH (n = 1, 2, 3, 4, and 5) have been found in bromo-substituted analogues of Tröger's bases.
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Affiliation(s)
- Diego Dusso
- INFIQC-Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
- Facultad de Ciencias Exactas Fisicoquímicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - Cristina Ramirez
- QUIAMM-INBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Alejandro Parise
- QUIAMM-INBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - P Lanza
- QUIAMM-INBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - D Mariano Vera
- QUIAMM-INBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina
| | - Carlos Chesta
- Facultad de Ciencias Exactas Fisicoquímicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina
| | - E Laura Moyano
- INFIQC-Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba, Argentina
| | - Novruz G Akhmedov
- Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia
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Riddell N, Jin UH, Safe S, Cheng Y, Chittim B, Konstantinov A, Parette R, Pena-Abaurrea M, Reiner EJ, Poirier D, Stefanac T, McAlees AJ, McCrindle R. Characterization and Biological Potency of Mono- to Tetra-Halogenated Carbazoles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:10658-10666. [PMID: 26226543 DOI: 10.1021/acs.est.5b02751] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
This paper deals with the characterization and aryl hydrocarbon receptor (AhR) agonist activities of a series of chlorinated, brominated, and mixed bromo/chlorocarbazoles, some of which have been identified in various environmental samples. Attention is directed here to the possibility that halogenated carbazoles may currently be emitted into the environment as a result of the production of carbazole-containing polymers present in a wide variety of electronic devices. We have found that any carbazole that is not substituted in the 1,3,6,8 positions may be lost during cleanup of environmental extracts if a multilayer column is utilized, as is common practice for polychlorinated dibenzo-p-dioxin (dioxin) and related compounds. In the present study, (1)H NMR spectral shift data for 11 relevant halogenated carbazoles are reported, along with their gas chromatographic separation and analysis by mass spectrometry. These characterization data allow for confident structural assignments and the derivation of possible correlations between structure and toxicity based on the halogenation patterns of the isomers investigated. Some halogenated carbazoles exhibit characteristics of persistent organic pollutants and their potential dioxin-like activity was further investigated. The structure-dependent induction of CYP1A1 and CYP1B1 gene expression in Ah-responsive MDA-MB-468 breast cancer cells by these carbazoles was similar to that observed for other dioxin-like compounds, and the magnitude of the fold induction responses for the most active halogenated carbazoles was similar to that observed for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 2,3,6,7-Tetrachlorocarbazole was one of the most active halogenated carbazoles and, like TCDD, contains 4 lateral substituents; however, the estimated relative effect potency for this compound (compared to TCDD) was 0.0001 and 0.0032, based on induction of CYP1A1 and CYP1B1 mRNA, respectively.
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Affiliation(s)
- Nicole Riddell
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
| | - Un-Ho Jin
- Department of Veterinary Physiology & Pharmacology, Texas A&M University , College Station, Texas 77843-4466, United States
| | - Stephen Safe
- Department of Veterinary Physiology & Pharmacology, Texas A&M University , College Station, Texas 77843-4466, United States
| | - Yating Cheng
- Department of Veterinary Physiology & Pharmacology, Texas A&M University , College Station, Texas 77843-4466, United States
| | - Brock Chittim
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
| | - Alex Konstantinov
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
| | - Robert Parette
- Matson & Associates, Inc. , 331 East Foster Avenue, State College, Pennsylvania 16801, United States
| | - Miren Pena-Abaurrea
- Ontario Ministry of the Environment , 125 Resources Road, Toronto, Ontario M9P 3 V6, Canada
- Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada
| | - Eric J Reiner
- Ontario Ministry of the Environment , 125 Resources Road, Toronto, Ontario M9P 3 V6, Canada
- Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada
| | - David Poirier
- Ontario Ministry of the Environment , 125 Resources Road, Toronto, Ontario M9P 3 V6, Canada
| | - Tomislav Stefanac
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
| | - Alan J McAlees
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
| | - Robert McCrindle
- Wellington Laboratories Inc. , 345 Southgate Drive, Guelph, Ontario Canada N1G 3M5
- Department of Chemistry, University of Guelph , Guelph, Ontario N1G 2W1, Canada
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Chen PT, Lin CK, Tsai CJ, Huang DY, Nien FY, Lin WW, Cheng WC. Expeditious synthesis of enantiopure, orthogonally protected bis-α-amino acids (OPBAAs) and their use in a study of Nod1 stimulation. Chem Asian J 2014; 10:474-82. [PMID: 25504924 DOI: 10.1002/asia.201403173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Indexed: 11/09/2022]
Abstract
A convenient approach towards the synthesis of orthogonally protected chiral bis-α-amino acids (OPBAAs) is described. The key transformations include: (1) a highly stereoselective conjugation (alkylation) of the Schöllkopf bis-lactim ethers and oxazolidinyl alkyl halides to build a backbone skeleton; and (2) our orthogonal protection strategy. A series of enantiopure OPBAAs bearing a variety of alkyl chain as a spacer; two stereogenic centers; and three protecting groups were prepared as examples. These versatile molecules were applied to the synthesis of biologically interesting di- or tri-peptide analogues, including chiral iE-meso-DAP and A-iE-meso-DAP, for the study of Nod1 activation in the innate immune response.
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Affiliation(s)
- Po-Ting Chen
- The Genomics Research Center, Academia Sinica, No. 128, Academia Road Sec. 2, Nankang District, Taipei, 11529 (Taiwan), Fax: (+886) 2-27899931
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