Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
6.7
4.6
Journals
Molecules
Special Issues
Stereogenic Centers
molecules-logo
Submit to Molecules Review for Molecules Propose a Special Issue

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Stereogenic Centers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Organic Chemistry".

Deadline for manuscript submissions: closed (30 July 2018) | Viewed by 66595

Special Issue Editor

Dr. Alejandro Baeza Carratalá

E-Mail Website
Guest Editor
Organic Chemistry Department and Instituto de Síntesis Orgánica, Universitat d’Alacant, 03690 Alicante, Spain
Interests: asymmetric catalysis; green chemistry; organocatalysis; metal catalysis
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The importance of having access to chiral molecules is a well-known fact for the scientific community. This is due to the fact that most of the biological activity that some molecules possess is associated to one of the all-possible enantiomers, which can interact differentially with chiral recognition entities, triggering distinct biochemical responses.

It is not surprising then that different methodologies have been developed in the last century, within the frame of so-called asymmetric synthesis, in order to tackle the challenging task of constructing such chiral compounds, as most of these strategies are based on the construction of stereogenic centers starting from racemic and/or pro-chiral compounds.

Thus, the aim of this Special Issue is to gather recent developments in the establishment of stereogenic centers in organic molecules. Therefore, asymmetric synthesis, kinetic resolutions, asymmetric catalysis (metal-, organo- and biocatalysis), among other strategies, as well as studies that help in the understanding of the mechanism behind these processes will be covered in this Special Issue.

Dr. Alejandro Baeza Carratalá
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Chirality
  • Stereogenic Centers
  • Asymmetric Synthesis
  • Asymmetric Catalysis
  • Enantiomers

Published Papers (14 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

3 pages, 192 KiB  
Editorial
Stereogenic Centers
by Alejandro Baeza
Molecules 2018, 23(11), 2964; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23112964 - 13 Nov 2018
Viewed by 2121
Abstract
The demand for chiral organic entities for different industrial purposes has grown exponentially in the last decades. [...] Full article
(This article belongs to the Special Issue Stereogenic Centers)

Research

Jump to: Editorial, Review

16 pages, 1742 KiB  
Communication
First Organocatalytic Asymmetric Synthesis of 1-Benzamido-1,4-Dihydropyridine Derivatives
by Fernando Auria-Luna, Eugenia Marqués-López and Raquel P. Herrera
Molecules 2018, 23(10), 2692; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23102692 - 19 Oct 2018
Cited by 13 | Viewed by 5116
Abstract
Preliminary results concerning the first asymmetric synthesis of highly functionalized 1-benzamido-1,4-dihydropyridine derivatives via the reaction of hydrazones with alkylidenemalononitriles in the presence of β-isocupreidine catalyst are reported. The moderate, but promising, enantioselectivity observed (40–54% ee), opens the door to a new area of [...] Read more.
Preliminary results concerning the first asymmetric synthesis of highly functionalized 1-benzamido-1,4-dihydropyridine derivatives via the reaction of hydrazones with alkylidenemalononitriles in the presence of β-isocupreidine catalyst are reported. The moderate, but promising, enantioselectivity observed (40–54% ee), opens the door to a new area of research for the asymmetric construction of new chiral 1,4-dihydropyridine derivatives, whose enantioselective catalytic preparation are still very limited. Moreover, the use of hydrazones for the enantioselective construction of chiral 1,4-dihydropyridines has been overlooked in the literature so far. Therefore, our research represents a pivotal example in this field which remains still unexplored. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Figure 1

11 pages, 2026 KiB  
Article
Asymmetric Synthesis of (−)-6-Desmethyl-Fluvirucinine A1 via Conformationally-Controlled Diastereoselective Lactam-Ring Expansions
by Hyunyoung Moon, Hojong Yoon, Changjin Lim, Jaebong Jang, Jong-Jae Yi, Jae Kyun Lee, Jeeyeon Lee, Younghwa Na, Woo Sung Son, Seok-Ho Kim and Young-Ger Suh
Molecules 2018, 23(9), 2351; https://doi.org/10.3390/molecules23092351 - 14 Sep 2018
Cited by 3 | Viewed by 3167
Abstract
The versatile synthesis of (−)-6-desmethyl-fluvirucinine A1 was accomplished at a 24% overall yield through a thirteen-step process from a known vinylpiperidine. The key part involved the elaboration of the distal stereocenters and a macrolactam skeleton via conformationally-induced diastereocontrol and the iterative aza-Claisen [...] Read more.
The versatile synthesis of (−)-6-desmethyl-fluvirucinine A1 was accomplished at a 24% overall yield through a thirteen-step process from a known vinylpiperidine. The key part involved the elaboration of the distal stereocenters and a macrolactam skeleton via conformationally-induced diastereocontrol and the iterative aza-Claisen rearrangements of lactam precursors. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

7 pages, 1250 KiB  
Communication
One-pot Fluorination and Organocatalytic Robinson Annulation for Asymmetric Synthesis of Mono- and Difluorinated Cyclohexenones
by Xin Huang, Weizhao Zhao, Xiaofeng Zhang, Miao Liu, Stanley N. S. Vasconcelos and Wei Zhang
Molecules 2018, 23(9), 2251; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23092251 - 04 Sep 2018
Cited by 8 | Viewed by 4436
Abstract
A one-pot fluorination and organocatalytic Robinson annulation sequence has been developed for asymmetric synthesis of 6-fluoroyclohex-2-en-1-ones and 4,6-difluorocyclohex-2-en-1-ones. The reactions promoted by cinchona alkaloid amine afforded products bearing two or three stereocenters in good to excellent yields with up to 99% ee and [...] Read more.
A one-pot fluorination and organocatalytic Robinson annulation sequence has been developed for asymmetric synthesis of 6-fluoroyclohex-2-en-1-ones and 4,6-difluorocyclohex-2-en-1-ones. The reactions promoted by cinchona alkaloid amine afforded products bearing two or three stereocenters in good to excellent yields with up to 99% ee and 20:1 dr. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

7 pages, 1914 KiB  
Communication
Oxidative Asymmetric Formal Aza-Diels–Alder Reactions of Tetrahydro-β-carboline with Enones in the Synthesis of Indoloquinolizidine-2-ones
by Xiang Wu, Shi-Bao Zhao, Lang-Lang Zheng and You-Gui Li
Molecules 2018, 23(9), 2228; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23092228 - 01 Sep 2018
Cited by 7 | Viewed by 4056
Abstract
Ru-catalyzed tandem amine oxidative dehydrogenation/formal aza-Diels–Alder reaction for enantio- and diastereoselective synthesis of indoloquinolizidine-2-ones from tetrahydro-β-carbolines and α,β-unsaturated ketones is described. The reaction proceeds via tandem ruthenium-catalyzed amine dehydrogenation using tert-butyl hydroperoxide (TBHP) as the oxidant and a chiral thiourea-catalyzed formal aza-[4 + [...] Read more.
Ru-catalyzed tandem amine oxidative dehydrogenation/formal aza-Diels–Alder reaction for enantio- and diastereoselective synthesis of indoloquinolizidine-2-ones from tetrahydro-β-carbolines and α,β-unsaturated ketones is described. The reaction proceeds via tandem ruthenium-catalyzed amine dehydrogenation using tert-butyl hydroperoxide (TBHP) as the oxidant and a chiral thiourea-catalyzed formal aza-[4 + 2] cycloaddition, providing a step-economical strategy for the synthesis of these valuable heterocyclic products. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

8 pages, 2707 KiB  
Article
Direct Asymmetric Reductive Amination for the Synthesis of (S)-Rivastigmine
by Guorui Gao, Shaozhi Du, Yang Yang, Xue Lei, Haizhou Huang and Mingxin Chang
Molecules 2018, 23(9), 2207; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23092207 - 31 Aug 2018
Cited by 16 | Viewed by 5629
Abstract
In this article we demonstrate how asymmetric total synthesis of (S)-rivastigmine has been achieved using direct asymmetric reductive amination as the key transformation in four steps. The route started with readily available and cheap m-hydroxyacetophenone, through esterification, asymmetric reductive amination, [...] Read more.
In this article we demonstrate how asymmetric total synthesis of (S)-rivastigmine has been achieved using direct asymmetric reductive amination as the key transformation in four steps. The route started with readily available and cheap m-hydroxyacetophenone, through esterification, asymmetric reductive amination, N-diphenylmethyl deprotection and reductive amination, to provide the final (S)-rivastigmine in 82% overall yield and 96% enantioselectivity. In the asymmetric reductive amination, catalysed by the iridium–phosphoramidite ligand complex and helped by some additives, the readily prepared 3-acetylphenyl ethyl(methyl)carbamate directly reductively coupled with diphenylmethanamine to yield the chiral amine product in 96% ee and 93% yield. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Figure 1

19 pages, 5429 KiB  
Article
Kinetic Resolution of Racemic 2-Hydroxyamides Using a Diphenylacetyl Component as an Acyl Source and a Chiral Acyl-Transfer Catalyst
by Takatsugu Murata, Tatsuya Kawanishi, Akihiro Sekiguchi, Ryo Ishikawa, Keisuke Ono, Kenya Nakata and Isamu Shiina
Molecules 2018, 23(8), 2003; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23082003 - 10 Aug 2018
Cited by 9 | Viewed by 4144
Abstract
Various optically active 2-hydroxyamide derivatives are produced based on the kinetic resolution of racemic 2-hydroxyamides with a diphenylacetyl component and (R)-benzotetramisole ((R)-BTM), a chiral acyl-transfer catalyst, via asymmetric esterification and acylation. It was revealed that a tertiary amide can [...] Read more.
Various optically active 2-hydroxyamide derivatives are produced based on the kinetic resolution of racemic 2-hydroxyamides with a diphenylacetyl component and (R)-benzotetramisole ((R)-BTM), a chiral acyl-transfer catalyst, via asymmetric esterification and acylation. It was revealed that a tertiary amide can be used with this novel protocol to achieve high selectivity (22 examples; s-value reaching over 250). The resulting chiral compounds could be transformed into other useful structures while maintaining their chirality. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Figure 1

9 pages, 877 KiB  
Article
One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination
by Peter P. Lankhorst, Jozef H. J. Van Rijn and Alexander L. L. Duchateau
Molecules 2018, 23(7), 1785; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23071785 - 20 Jul 2018
Cited by 15 | Viewed by 5125
Abstract
The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of [...] Read more.
The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

10 pages, 3100 KiB  
Article
Chiral 2-Aminobenzimidazole as Bifunctional Catalyst in the Asymmetric Electrophilic Amination of Unprotected 3-Substituted Oxindoles
by Llorenç Benavent, Alejandro Baeza and Megan Freckleton
Molecules 2018, 23(6), 1374; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23061374 - 06 Jun 2018
Cited by 11 | Viewed by 3865
Abstract
The use of readily available chiral trans-cyclohexanediamine-benzimidazole derivatives as bifunctional organocatalysts in the asymmetric electrophilic amination of unprotected 3-substituted oxindoles is presented. Different organocatalysts were evaluated; the most successful one contained a dimethylamino moiety (5). With this catalyst under optimized [...] Read more.
The use of readily available chiral trans-cyclohexanediamine-benzimidazole derivatives as bifunctional organocatalysts in the asymmetric electrophilic amination of unprotected 3-substituted oxindoles is presented. Different organocatalysts were evaluated; the most successful one contained a dimethylamino moiety (5). With this catalyst under optimized conditions, different oxindoles containing a wide variety of substituents at the 3-position were aminated in good yields and with good to excellent enantioselectivities using di-tert-butylazodicarboxylate as the aminating agent. The procedure proved to be also efficient for the amination of 3-substituted benzofuranones, although with moderate results. A bifunctional role of the catalyst, acting as Brønsted base and hydrogen bond donor, is proposed according to the experimental results observed. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Figure 1

12 pages, 3684 KiB  
Communication
Catalytic Enantioselective Addition of Organozirconium Reagents to Aldehydes
by Ricard Solà, Marcos Veguillas, María José González-Soria, Nicholas Carter, M. Angeles Fernández-Ibáñez and Beatriz Maciá
Molecules 2018, 23(4), 961; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23040961 - 20 Apr 2018
Cited by 4 | Viewed by 5586
Abstract
A catalytic enantioselective addition reaction of alkylzirconium species to aromatic aldehydes is reported. The reaction, facilitated by a chiral nonracemic diol ligand complex with Ti(OiPr)4, proceeds under mild and convenient conditions, and no premade organometallic reagents are required since [...] Read more.
A catalytic enantioselective addition reaction of alkylzirconium species to aromatic aldehydes is reported. The reaction, facilitated by a chiral nonracemic diol ligand complex with Ti(OiPr)4, proceeds under mild and convenient conditions, and no premade organometallic reagents are required since the alkylzirconium nucleophiles are generated in situ by hydrozirconation of alkenes with the Schwartz reagent. The methodology is compatible with functionalized nucleophiles and a broad range of aromatic aldehydes. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

13 pages, 1803 KiB  
Article
Asymmetric Conjugate Addition of α,α-Disubstituted Aldehydes to Nitroalkenes Organocatalyzed by Chiral Monosalicylamides from trans-Cyclohexane-1,2-Diamines
by José R. Martínez-Guillén, Jesús Flores-Ferrándiz, Cecilia Gómez, Enrique Gómez-Bengoa and Rafael Chinchilla
Molecules 2018, 23(1), 141; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23010141 - 11 Jan 2018
Cited by 8 | Viewed by 4205
Abstract
Primary amine-salicylamides derived from chiral trans-cyclohexane-1,2-diamines are used as organocatalysts for the enantioselective conjugate addition of α,α-disubstituted aldehydes to arylated and heteroarylated nitroalkenes. The reaction is performed in the presence of 4-dimethylaminopyridine as an additive in dichloromethane as a solvent at room [...] Read more.
Primary amine-salicylamides derived from chiral trans-cyclohexane-1,2-diamines are used as organocatalysts for the enantioselective conjugate addition of α,α-disubstituted aldehydes to arylated and heteroarylated nitroalkenes. The reaction is performed in the presence of 4-dimethylaminopyridine as an additive in dichloromethane as a solvent at room temperature. The corresponding enantioenriched γ-nitroaldehydes are obtained with enantioselectivities up to 95%. Theoretical calculations are used to justify the reasons of the stereoinduction. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

Review

Jump to: Editorial, Research

16 pages, 7307 KiB  
Review
Unsymmetrical Diboron Reagents: Application in Borylation Reactions of Unsaturated Bonds
by Siyi Ding, Liang Xu and Zongcheng Miao
Molecules 2019, 24(7), 1325; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules24071325 - 04 Apr 2019
Cited by 21 | Viewed by 4533
Abstract
In the past decades, borylation reactions have received extensive research interest and have developed into effective tools in the synthesis of versatile organoboron compounds. Boranes and symmetrical diboron compounds are commonly utilized as borylating reagents in these transformations, especially in the borylation reactions [...] Read more.
In the past decades, borylation reactions have received extensive research interest and have developed into effective tools in the synthesis of versatile organoboron compounds. Boranes and symmetrical diboron compounds are commonly utilized as borylating reagents in these transformations, especially in the borylation reactions of unsaturated bonds. More recently, several types of unsymmetrical diboron reagents have been synthesized and applied in these borylation reactions, allowing for complementary chemo- and regioselectivity. This review aimed to highlight the recent development in this rising research field, focusing on new reactivity and selectivity that originates from the use of these unsymmetrical diboron reagents. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

17 pages, 4736 KiB  
Review
Recent Advances in the Catalytic Asymmetric Reactions of Oxaziridines
by Qiao Ren, Wen Yang, Yunfei Lan, Xurong Qin, Youzhou He and Lujiang Yuan
Molecules 2018, 23(10), 2656; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23102656 - 16 Oct 2018
Cited by 13 | Viewed by 5262
Abstract
Oxaziridines have emerged as powerful and elegant oxygen- and nitrogen-transfer agents for a broad array of nucleophiles, due to the remarkably high and tunable reactivities. However, the asymmetric catalysis involving oxaziridines is still in its infancy. Herein, this review aims to examine recent [...] Read more.
Oxaziridines have emerged as powerful and elegant oxygen- and nitrogen-transfer agents for a broad array of nucleophiles, due to the remarkably high and tunable reactivities. However, the asymmetric catalysis involving oxaziridines is still in its infancy. Herein, this review aims to examine recent advances in the catalytic asymmetric transformations of oxaziridines, including oxidation, amination, cycloaddition and deracemization. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Figure 1

14 pages, 3938 KiB  
Review
Practical Enantioselective Reduction of Ketones Using Oxazaborolidine Catalysts Generated In Situ from Chiral Lactam Alcohols
by Yasuhiro Kawanami and Ryo C. Yanagita
Molecules 2018, 23(10), 2408; https://0-doi-org.brum.beds.ac.uk/10.3390/molecules23102408 - 20 Sep 2018
Cited by 11 | Viewed by 8197
Abstract
Oxazaborolidine catalyst (CBS catalyst) has been extensively used for catalytic borane reduction with a predictable absolute stereochemistry and high enantioselectivity. However, the use of isolated CBS catalyst sometimes has the drawback of low reproducibility due to the aging of the CBS catalyst during [...] Read more.
Oxazaborolidine catalyst (CBS catalyst) has been extensively used for catalytic borane reduction with a predictable absolute stereochemistry and high enantioselectivity. However, the use of isolated CBS catalyst sometimes has the drawback of low reproducibility due to the aging of the CBS catalyst during storage. Therefore, we investigated a more reliable and practical method for the reduction of a variety of ketones including challenging substrates, primary aliphatic ketones, α,β-enones, and trifluoromethyl ketones. This review surveys the developments in borane reduction using oxazaborolidine catalysts generated in situ from chiral lactam alcohols and borane. Full article
(This article belongs to the Special Issue Stereogenic Centers)
►▼ Show Figures

Graphical abstract

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-14
Back to TopTop