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Journal articles on the topic 'Quaternary carbons'

Author: Grafiati

Published: 5 June 2025

Last updated: 1 August 2025

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1

ROUHI, MAUREEN. "QUATERNARY CARBONS." Chemical & Engineering News 79, no. 19 (2001): 53. http://dx.doi.org/10.1021/cen-v079n019.p053.

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2

Li, Bi-Jie, and Xin Sun. "Acyclic Quaternary Carbon Stereocenters through Transition-Metal-Catalyzed Enantioselective Functionalization of Unsaturated Hydrocarbons." Synthesis 54, no. 09 (2022): 2103–18. http://dx.doi.org/10.1055/s-0040-1719899.

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AbstractAcyclic quaternary carbon stereocenters occur frequently in natural products, bioactive molecules, and pharmaceutical compounds. Construction of a carbon stereogenic center attached to four different carbons with defined spatial arrangement is a daunting challenge in asymmetric catalysis. Significant efforts have been directed towards the stereoselective construction of such acyclic quaternary carbon stereocenters. In particular, catalytic generation of acyclic quaternary carbon stereocenters through functionalization of unsaturated hydrocarbons is an extremely attractive approach beca

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3

Kita, Yasuyuki, and Hiromichi Fujioka. "Enantioselective constructions of quaternary carbons and their application to the asymmetric total syntheses of fredericamycin A and discorhabdin A." Pure and Applied Chemistry 79, no. 4 (2007): 701–13. http://dx.doi.org/10.1351/pac200779040701.

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An efficient enantioselective construction of quaternary carbons including spiro carbons is an area of intense interest due to the importance of these units as components of biologically active natural products. Prominent methods are presented for the synthesis of chiral, nonracemic quaternary carbon centers by (i) stereospecific rearrangement of optically active epoxides, (ii) enzyme-catalyzed resolution, and (iii) hypervalent iodine reagent-induced ipso-substitution of para-substituted phenol derivatives. These methods were applied to the total syntheses of fredericamycin A and discorhabdin

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4

Palao, Eduardo, Enol López, Iván Torres-Moya, Antonio de la Hoz, Ángel Díaz-Ortiz, and Jesús Alcázar. "Formation of quaternary carbons through cobalt-catalyzed C(sp3)–C(sp3) Negishi cross-coupling." Chemical Communications 56, no. 59 (2020): 8210–13. http://dx.doi.org/10.1039/d0cc02734k.

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5

Eggert, Alina, Christoph Etling, Dennis Lübken, Marius Saxarra, and Markus Kalesse. "Contiguous Quaternary Carbons: A Selection of Total Syntheses." Molecules 25, no. 17 (2020): 3841. http://dx.doi.org/10.3390/molecules25173841.

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Contiguous quaternary carbons in terpene natural products remain a major challenge in total synthesis. Synthetic strategies to overcome this challenge will be a pivotal prerequisite to the medicinal application of natural products and their analogs or derivatives. In this review, we cover syntheses of natural products that exhibit a dense assembly of quaternary carbons and whose syntheses were uncompleted until recently. While discussing their syntheses, we not only cover the most recent total syntheses but also provide an update on the status quo of modern syntheses of complex natural product

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6

Gutman, Ivan, Dusica Vidovic, and Dragan Stevanovic. "Chemical applications of the Laplacian spectrum. VI On the largest Laplacian eigenvalue of alkanes." Journal of the Serbian Chemical Society 67, no. 6 (2002): 407–13. http://dx.doi.org/10.2298/jsc0206407g.

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The largest Lapacian eigenvalue ?1 of the molecular graph is a quantity important in the theory of the photoelectron spectra of saturated hydrocarbons. It is shown that in the case of alkanes, the presence or absence of quaternary carbon atoms is the main structural feature on which ?1 depends. Within sets of all alkanes with a given number of carbon atoms the species (with and without quaternary carbons atoms) whose ?1-values are minimal and maximal are determined.

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7

Gan, Xu-cheng, Benxiang Zhang, Nathan Dao, et al. "Carbon quaternization of redox active esters and olefins by decarboxylative coupling." Science 384, no. 6691 (2024): 113–18. http://dx.doi.org/10.1126/science.adn5619.

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The synthesis of quaternary carbons often requires numerous steps and complex conditions or harsh reagents that act on heavily engineered substrates. This is largely a consequence of conventional polar-bond retrosynthetic disconnections that in turn require multiple functional group interconversions, redox manipulations, and protecting group chemistry. Here, we report a simple catalyst and reductant combination that converts two types of feedstock chemicals, carboxylic acids and olefins, into tetrasubstituted carbons through quaternization of radical intermediates. An iron porphyrin catalyst a

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8

Liu, Yiyang, Marc Liniger, Ryan M. McFadden, et al. "Formal total syntheses of classic natural product target molecules via palladium-catalyzed enantioselective alkylation." Beilstein Journal of Organic Chemistry 10 (October 28, 2014): 2501–12. http://dx.doi.org/10.3762/bjoc.10.261.

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Pd-catalyzed enantioselective alkylation in conjunction with further synthetic elaboration enables the formal total syntheses of a number of “classic” natural product target molecules. This publication highlights recent methods for setting quaternary and tetrasubstituted tertiary carbon stereocenters to address the synthetic hurdles encountered over many decades across multiple compound classes spanning carbohydrate derivatives, terpenes, and alkaloids. These enantioselective methods will impact both academic and industrial settings, where the synthesis of stereogenic quaternary carbons is a c

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9

Krebs, H. C., and T. Carl. "Retrorsine: Correct Assignment of Quaternary Carbons." Magnetic Resonance in Chemistry 34, no. 12 (1996): 1046–47. http://dx.doi.org/10.1002/(sici)1097-458x(199612)34:12<1046::aid-omr12>3.0.co;2-u.

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10

Villalgordo-Hernández, David, Aida Grau-Atienza, Antonio A. García-Marín, Enrique V. Ramos-Fernández, and Javier Narciso. "Manufacture of Carbon Materials with High Nitrogen Content." Materials 15, no. 7 (2022): 2415. http://dx.doi.org/10.3390/ma15072415.

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Nowadays one of the biggest challenges for carbon materials is their use in CO2 capture and their use as electrocatalysts in the oxygen reduction reaction (ORR). In both cases, it is necessary to dope the carbon with nitrogen species. Conventional methods to prepare nitrogen doped carbons such as melamine carbonization or NH3 treatment generate nitrogen doped carbons with insufficient nitrogen content. In the present research, a series of activated carbons derived from MOFs (ZIF-8, ZIF-67) are presented. Activated carbons have been prepared in a single step, by pyrolysis of the MOF in an inert

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11

Sairenji, Shiho, Takashi Kikuchi, Mohamed Ahmed Abozeid, et al. "Determination of the absolute configuration of compounds bearing chiral quaternary carbon centers using the crystalline sponge method." Chemical Science 8, no. 7 (2017): 5132–36. http://dx.doi.org/10.1039/c7sc01524k.

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12

Green, Samantha A., Tucker R. Huffman, Ruairí O. McCourt, Vincent van der Puyl, and Ryan A. Shenvi. "Hydroalkylation of Olefins To Form Quaternary Carbons." Journal of the American Chemical Society 141, no. 19 (2019): 7709–14. http://dx.doi.org/10.1021/jacs.9b02844.

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13

G., A. Nagana Gowda, Murali N., S. Joshi B., Roy Raja, and L. Khetrapal C. "Pulse schemes for detection of quaternary carbons with and without proton decoupling." Journal of Indian Chemical Society Vol. 80, APr 2003 (2003): 367–71. https://doi.org/10.5281/zenodo.5839665.

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Centre of Biomedical Magnetic Resonance, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Raebareli Road, Lucknow-226 014, India <em>E-mail :</em> clk@sgpgi.ac.in clkhetrapal@hotmail.com Fax : 91-522-668215 Varian NMR Systems, 3120 Hansen Way M/S D-298, Palo Alto, CA 94304-103, USA NMR Laboratory, Division of RSIC, Central Drug Research Institute, Lucknow- 226 001, India <em>Manuscript received 20 September 2002</em> Four new pulse sequences are proposed for the detection of quaternary carbons. The primary, secondary and tertiary (CH<sub>3</sub>, CH<sub>2</sub> and CH) carbons are su

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14

Li, You, Jingpeng Han, Han Luo, Qiaoyu An, Xiao-Ping Cao, and Baosheng Li. "Access to Benzylic Quaternary Carbons from Aromatic Ketones." Organic Letters 21, no. 15 (2019): 6050–53. http://dx.doi.org/10.1021/acs.orglett.9b02204.

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15

Fiala, Radovan, Markéta L. Munzarová, and Vladimír Sklenář. "Experiments for correlating quaternary carbons in RNA bases." Journal of Biomolecular NMR 29, no. 4 (2004): 477–90. http://dx.doi.org/10.1023/b:jnmr.0000034358.12599.d1.

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16

Liu, Jia-Li, Ze-Fan Zhu, and Feng Liu. "Cyanofluorination of vinyl ethers enabled by electron donor–acceptor complexes." Organic Chemistry Frontiers 6, no. 2 (2019): 241–44. http://dx.doi.org/10.1039/c8qo01143e.

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The reaction is operationally simple and conducted under ambient conditions, allowing the access to highly functionalized α-alkoxy-β-fluoronitriles bearing quaternary carbons that are difficult to access by existing methods.

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17

Han, Wenyong, Yihui Yang, Yingguang Zhu, and Yian Shi. "A facile copper(i)-catalyzed homo-coupling of indanone derivatives using diaziridinone under mild conditions." Organic & Biomolecular Chemistry 17, no. 29 (2019): 6998–7001. http://dx.doi.org/10.1039/c9ob00901a.

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A variety of 1,4-dicarbonyl compounds containing vicinal quaternary carbons are efficiently generated in high yields with high diastereoselectivities via Cu(i)-catalyzed homo-coupling of indanone derivatives using diaziridinone as an oxidant.

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18

Liu, Qiang, Ming Ke, Feng Liu, Pei Yu, Haiqiang Hu, and Changchun Li. "High-performance removal of methyl mercaptan by nitrogen-rich coconut shell activated carbon." RSC Advances 7, no. 37 (2017): 22892–99. http://dx.doi.org/10.1039/c7ra03227g.

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Nitrogen-rich coconut shell activated carbons were prepared with high CH<sub>3</sub>SH capacity and easy regeneration. The catalytic activity is closely related to the contents of pyridinic nitrogen and quaternary nitrogen.

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19

Tang, Jiaxu, Yuhai Tang, Xiaonan Wang, et al. "Regioselective cascade annulation of indoles with alkynediones for construction of functionalized tetrahydrocarbazoles triggered by Cp*RhIII-catalyzed C–H activation." Organic Chemistry Frontiers 8, no. 14 (2021): 3809–14. http://dx.doi.org/10.1039/d1qo00616a.

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An efficient regioselective and stereoselective cascade annulation of indoles with alkynediones has been developed for construction of free (NH) tetrahydrocarbazoles with continuous quaternary carbons via Cp*Rh<sup>III</sup>-catalyzed indole C2–H activation.

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20

Flores, Océane, Patrick Wagner, and Jean Suffert. "Cyclocarbopalladation/Stille Cascade: Stereoselective Access to Quaternary Functionalized Carbons." Organic Letters 23, no. 16 (2021): 6568–72. http://dx.doi.org/10.1021/acs.orglett.1c02400.

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21

Sadiq, Abdul, and Thomas C. Nugent. "Catalytic Access to Succinimide Products Containing Stereogenic Quaternary Carbons." ChemistrySelect 5, no. 38 (2020): 11934–38. http://dx.doi.org/10.1002/slct.202003664.

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22

Gowda, G. A. Nagana. "One-dimensional pulse technique for detection of quaternary carbons." Magnetic Resonance in Chemistry 39, no. 10 (2001): 581–85. http://dx.doi.org/10.1002/mrc.882.

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23

Gao, Chang, Jingjing Li, Jipan Yu, Haijun Yang, and Hua Fu. "Visible-light photoredox synthesis of internal alkynes containing quaternary carbons." Chemical Communications 52, no. 45 (2016): 7292–94. http://dx.doi.org/10.1039/c6cc01632d.

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A novel and efficient visible-light photoredox method for the synthesis of internal alkynes containing quaternary carbons has been developed via coupling reactions of N-phthalimidoyl oxalates of tert-alcohols with 1-(2-(arylsulfonyl)ethynyl)benzenes. The reactions proceeded well at room temperature with good functional group tolerability.

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24

Wang, Xiaoguang, Yanli Zhang, Jing Li, Guizhai Zhang, and Xiaoming Li. "Enhance Cr(VI) removal by quaternary amine-anchoring activated carbons." Journal of the Taiwan Institute of Chemical Engineers 58 (January 2016): 434–40. http://dx.doi.org/10.1016/j.jtice.2015.06.034.

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25

DePorre, Yvonne C., James R. Annand, Sukanta Bar, and Corinna S. Schindler. "Lewis-Base-Catalyzed Reductive Aldol Reaction To Access Quaternary Carbons." Organic Letters 20, no. 9 (2018): 2580–84. http://dx.doi.org/10.1021/acs.orglett.8b00507.

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26

Pogliani, Lionello. "Longitudinal Relaxation of the Quaternary Carbons of Some Phosphine Oxides." Spectroscopy Letters 25, no. 6 (1992): 831–40. http://dx.doi.org/10.1080/00387019208020715.

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27

KRIEF, A., J. L. LABOUREUR, M. HOBE, and P. BARBEAUX. "ChemInform Abstract: Original Syntheses of Molecules Containing Adjacent Quaternary Carbons." ChemInform 22, no. 39 (2010): no. http://dx.doi.org/10.1002/chin.199139289.

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28

Tabuchi, Toshiki, Daisuke Urabe, and Masayuki Inoue. "Asymmetric synthesis of a highly functionalized bicyclo[3.2.2]nonene derivative." Beilstein Journal of Organic Chemistry 9 (April 4, 2013): 655–63. http://dx.doi.org/10.3762/bjoc.9.74.

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The stereoselective Diels–Alder reaction between an optically active 1,4-dimethylcycloheptadiene and acrolein was effectively promoted by TBSOTf to produce a bicyclo[3.2.2]nonene derivative bearing two quaternary carbons. Seven additional transformations from the obtained bicycle delivered the C 2-symmetric bicyclo[3.3.2]decene derivative, a key intermediate in our synthetic study of ryanodine.

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29

Nakamura, Hugh, Manami Kawakami, Chihiro Tsukano, and Yoshiji Takemoto. "Construction of the ACDE Ring System of Calyciphylline A-type Alkaloids via Intramolecular Diels–Alder Reaction of a Tetrasubstituted Olefin." Synlett 30, no. 20 (2019): 2253–57. http://dx.doi.org/10.1055/s-0039-1690267.

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A concise synthesis of the ACDE tetracyclic ring system of calyciphylline A-type alkaloids was investigated. The intramolecular Diels–Alder reaction of a tetrasubstituted olefin with furan enabled the construction of the ACD ring system bearing two contiguous quaternary carbons in one step, and subsequent intramolecular [3+2] cycloaddition successfully gave the E ring.

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30

Morais, Rafael G., Natalia Rey-Raap, José L. Figueiredo, and Manuel F. R. Pereira. "Insights into the Electrocatalytic Activity of Fe,N-Glucose/Carbon Nanotube Hybrids for the Oxygen Reduction Reaction." C 10, no. 2 (2024): 47. http://dx.doi.org/10.3390/c10020047.

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Glucose-derived carbon hybrids were synthesized by hydrothermal treatment in the presence of oxidized carbon nanotubes. Additionally, iron and nitrogen functionalities were incorporated into the carbon structure using different methodologies. The introduction of iron and nitrogen in a single step under a H2 atmosphere favored the formation of quaternary nitrogen and oxidized nitrogen, whereas the incorporation of nitrogen under an N2 atmosphere after doping the hybrids with iron mainly produced pyridinic nitrogen. The samples were characterized by scanning electron microscopy, X-ray spectrosco

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31

Abu-Daabes, Malyuba A., Edrees Abu Zeitoun, and Wafa Mazi. "Competitive Adsorption of Quaternary Metal Ions, Ni2+, Mn2+, Cr6+, and Cd2+, on Acid-Treated Activated Carbon." Water 15, no. 6 (2023): 1070. http://dx.doi.org/10.3390/w15061070.

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This paper examined the competitive removal of metal ions from quaternary aqueous solutions containing Ni2+, Mn2+, Cr6+, and Cd2+ using adsorption on both acid-modified and unmodified activated carbon. Activated carbon (AC) was oxidized with nitric acid, both in granular (AGC) and powder (APC) forms, and tested for the competitive adsorption of Ni2+, Mn2+, Cr6+, and Cd2+ from an aqueous solution. Surface oxidation led to a reduction in BET surface area and HK pore width and an increase in the intensities of hydroxyl and carboxyl functional groups for both AGC and APC compared to unmodified act

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32

Fu, Xingyu, Minsi Shi, Dingyang Chen, Xinyue Zhao, Tingting Jiang, and Rui Zhao. "Theory-Driven Tailoring of the Microenvironment of Quaternary Ammonium Binding Sites on Electrospun Nanofibers for Efficient Bilirubin Removal in Hemoperfusion." Polymers 16, no. 11 (2024): 1599. http://dx.doi.org/10.3390/polym16111599.

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Efficient adsorbents for excess bilirubin removal are extremely important for the treatment of hyperbilirubinemia. However, traditional adsorbents, such as activated carbons and ion-exchange resins, still suffer from dissatisfactory adsorption performance and poor blood compatibility. Herein, we adopted a rational design strategy guided by density functional theory (DFT) calculations to prepare blood-compatible quaternary ammonium group grafted electrospun polyacrylonitrile nanofiber adsorbents. The calculation analysis and adsorption experiments were used to investigate the structure–function

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33

Morais, Rafael Gomes, Natalia Rey-Raap, José Luís Figueiredo, and Manuel Fernando Ribeiro Pereira. "Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction." Beilstein Journal of Nanotechnology 10 (May 21, 2019): 1089–102. http://dx.doi.org/10.3762/bjnano.10.109.

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Nitrogen-doped biomass-derived carbon materials were prepared by hydrothermal carbonization of glucose, and their textural and chemical properties were subsequently tailored to achieve materials with enhanced electrochemical performance towards the oxygen reduction reaction. Carbonization and physical activation were applied to modify the textural properties, while nitrogen functionalities were incorporated via different N-doping methodologies (ball milling and conventional methods) using melamine. A direct relationship between the microporosity of the activated carbons and the limiting curren

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34

Crimmins, Michael T., John D. Knight, Philip S. Williams, and Yan Zhang. "Stereoselective Synthesis of Quaternary Carbons via the Dianionic Ireland–Claisen Rearrangement." Organic Letters 16, no. 9 (2014): 2458–61. http://dx.doi.org/10.1021/ol5008422.

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35

Peterson, E. A., and L. E. Overman. "Contiguous stereogenic quaternary carbons: A daunting challenge in natural products synthesis." Proceedings of the National Academy of Sciences 101, no. 33 (2004): 11943–48. http://dx.doi.org/10.1073/pnas.0402416101.

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36

Tsuchiya, Naoki, and Takashi Nishikata. "Construction of Vicinal Quaternary Carbons via Cu-catalyzed Dearomative Radical Addition." Chemistry Letters 48, no. 7 (2019): 718–21. http://dx.doi.org/10.1246/cl.190247.

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37

Byrne, Timothy M., Xin Gu, Pin Hou, Fred S. Cannon, Nicole R. Brown, and César Nieto-Delgado. "Quaternary nitrogen activated carbons for removal of perchlorate with electrochemical regeneration." Carbon 73 (July 2014): 1–12. http://dx.doi.org/10.1016/j.carbon.2014.02.020.

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38

Wu, Ke-Xin, Yi-Ze Xu, Liang Cheng, Run-Shi Wu, Peng-Ze Liu, and Da-Zhen Xu. "Iron-catalyzed oxidative bis-arylation of indolin-2-ones for direct construction of quaternary carbons." Green Chemistry 23, no. 21 (2021): 8448–52. http://dx.doi.org/10.1039/d1gc02886c.

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The cross-dehydrogenative coupling protocol is catalyzed by a simple iron salt, and air is used as the terminal oxidant under very mild conditions, offering a novel synthetic method for the direct construction of all-carbon quaternary centers.

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39

Abdellaoui, O., M. Chraibi, M. K. Skalli, et al. "Synthesis and Antibacterial Evaluation of Three Quaternary Ammonium Surfactants Based on Isatin." Asian Journal of Chemistry 34, no. 5 (2022): 1274–78. http://dx.doi.org/10.14233/ajchem.2022.23577.

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In present study, several isatin-derived quaternary ammonium surfactants with different carbon chain lengths were designed and synthesized. They were synthesized by alkylation of indoline-2,3-dione with various dibromo-alkanes, then quaternization with trimethylamine. Nuclear magnetic resonance (1H NMR, 13C NMR) and mass spectroscopy were employed to examine their chemical structures. Further, the critical micelle concentrations (CMC) value of surfactants synthesized was determined in an aqueous solution using electrical conductivity. The synthesized surfactants had CMC ranging from 0.01 to 0.

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40

Klein, Robert F. X., Václav Horák, and Arthur G. Anderson. "NMR Spectroscopic Studies of Thialene (Cyclopenta[b]thiapyran) and Isothialene (Cyclopenta[c]thiapyran)." Collection of Czechoslovak Chemical Communications 58, no. 1 (1993): 113–20. http://dx.doi.org/10.1135/cccc19930113.

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1H and 13C NMR spectral parameters are reported for the S-pseudoazulenes thialene (cyclopenta[b]thiapyran) (I) and isothialene (cyclopenta[c]thiapyran) (II). Both compounds display complex first order spectra, with thialene having 10 and isothialene 14 of 15 possible coupling constants. Complete unambiguous assignments of all protons and non-quaternary carbons were made via 2-dimensional NMR techniques and PPP-SCF π-electron density/chemical shift and π-bond order/vicinal coupling constant correlations.

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41

Aiello, Federica, Alessandra Recchimurzo, Federica Balzano, Gloria Uccello Barretta, and Federica Cefalì. "A Thiourea Derivative of 2-[(1R)-1-Aminoethyl]phenol as a Chiral Sensor for the Determination of the Absolute Configuration of N-3,5-Dinitrobenzoyl Derivatives of Amino Acids." Molecules 29, no. 6 (2024): 1319. http://dx.doi.org/10.3390/molecules29061319.

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In the exploration of chiral solvating agents (CSAs) for nuclear magnetic resonance (NMR) spectroscopy designed for the chiral analysis of amino acid derivatives, notable advancements have been made with thiourea–CSAs. 1-TU, derived from 2-[(1R)-1-aminoethyl]phenol and benzoyl isothiocyanate, is effective in the enantiodifferentiation of N-3,5-dinitrobenzoyl (N-DNB) amino acids. In order to broaden the application of 1-TU for configurational assignment, enantiomerically enriched N-DNB amino acids were analyzed via NMR. A robust correlation was established between the relative position of speci

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42

Murphy, John J., David Bastida, Suva Paria, Maurizio Fagnoni, and Paolo Melchiorre. "Asymmetric catalytic formation of quaternary carbons by iminium ion trapping of radicals." Nature 532, no. 7598 (2016): 218–22. http://dx.doi.org/10.1038/nature17438.

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43

Dalko, Peter I., and Yves Langlois. "Stereoselective Synthesis of Quaternary Benzylic Carbons UsingC2Symmetric Imidazolines and Tetrahydrofuran as Electrophile." Journal of Organic Chemistry 63, no. 23 (1998): 8107–17. http://dx.doi.org/10.1021/jo980289r.

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44

Matsuta, Yumiko, Takayuki Kobari, Sachiko Kurashima, et al. "Highly diastereoselective Claisen rearrangement leading to vicinal quaternary carbons construction of oxindoles." Tetrahedron Letters 52, no. 46 (2011): 6199–202. http://dx.doi.org/10.1016/j.tetlet.2011.09.059.

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45

Rugutt, Joseph K., Nikolaus H. Fischer, Marcus A. Nauman, Thomas J. Schmidt, and Dana K. Berner. "13C-NMR Assignments for Methyls and Quaternary Carbons of the Limonoid Obacunone." Spectroscopy Letters 29, no. 4 (1996): 711–26. http://dx.doi.org/10.1080/00387019608007063.

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46

Srikrishna, A. "Regio- and stereospecific construction of vicinal quaternary carbons: total synthesis of (±)-albene." Phytochemistry 40, no. 6 (1995): 1699–704. http://dx.doi.org/10.1016/0031-9422(95)00592-u.

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47

Welle, Alexandre, Julien Petrignet, Bernard Tinant, Johan Wouters, and Olivier Riant. "Copper-Catalysed Domino Silylative Aldol Reaction Leading to Stereocontrolled Chiral Quaternary Carbons." Chemistry - A European Journal 16, no. 36 (2010): 10980–83. http://dx.doi.org/10.1002/chem.201000907.

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48

Bigler, Peter, Rainer Kümmerle, and Wolfgang Bermel. "Multiplicity editing including quaternary carbons: improved performance for the13C-DEPTQ pulse sequence." Magnetic Resonance in Chemistry 45, no. 6 (2007): 469–72. http://dx.doi.org/10.1002/mrc.1993.

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49

Dondas, H., José Sansano, Samet Belveren, et al. "From Bioactive Pyrrolidino[3,4-c]pyrrolidines to more Bioactive Pyrrolidino[3,4-b]pyrrolidines via Ring-Opening/Ring-Closing Promoted by Sodium Methoxide." Synthesis 51, no. 07 (2018): 1565–77. http://dx.doi.org/10.1055/s-0037-1611356.

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The process involving a rearrangement of pyrrolidino[3,4-c]pyrrolidine to another pyrrolidino[3,4-b]pyrrolidine using sodium methoxide as base is fully studied. The effects of the substituents are analyzed during the ring-opening/ring-closing sequence. Computational studies are also performed to explain the importance of susbstituents and quaternary carbons, especially when the (3-indolyl)methyl is present in the starting material. Finally, all the samples are evaluated as potential candidates for antibacterial and antimycobacterial activities.

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Kessler, H., W. Bermel, and C. Griesinger. "Determination of carbon-carbon connectivities, assignment of quaternary carbons, and extraction of carbon-carbon coupling constants by carbon-relayed hydrogen-carbon spectroscopy." Journal of Magnetic Resonance (1969) 62, no. 3 (1985): 573–79. http://dx.doi.org/10.1016/0022-2364(85)90231-8.

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