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Remmerswaal WA, de Jong T, van de Vrande KNA, Louwersheimer R, Verwaal T, Filippov DV, Codée JDC, Hansen T. Backside versus Frontside S N2 Reactions of Alkyl Triflates and Alcohols. Chemistry 2024; 30:e202400590. [PMID: 38385647 DOI: 10.1002/chem.202400590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 02/22/2024] [Indexed: 02/23/2024]
Abstract
Nucleophilic substitution reactions are elementary reactions in organic chemistry that are used in many synthetic routes. By quantum chemical methods, we have investigated the intrinsic competition between the backside SN2 (SN2-b) and frontside SN2 (SN2-f) pathways using a set of simple alkyl triflates as the electrophile in combination with a systematic series of phenols and partially fluorinated ethanol nucleophiles. It is revealed how and why the well-established mechanistic preference for the SN2-b pathway slowly erodes and can even be overruled by the unusual SN2-f substitution mechanism going from strong to weak alcohol nucleophiles. Activation strain analyses disclose that the SN2-b pathway is favored for strong alcohol nucleophiles because of the well-known intrinsically more efficient approach to the electrophile resulting in a more stabilizing nucleophile-electrophile interaction. In contrast, the preference of weaker alcohol nucleophiles shifts to the SN2-f pathway, benefiting from a stabilizing hydrogen bond interaction between the incoming alcohol and the leaving group. This hydrogen bond interaction is strengthened by the increased acidity of the weaker alcohol nucleophiles, thereby steering the mechanistic preference toward the frontside SN2 pathway.
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Affiliation(s)
- Wouter A Remmerswaal
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Tjeerd de Jong
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Koen N A van de Vrande
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Rick Louwersheimer
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Thomas Verwaal
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Dmitri V Filippov
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Jeroen D C Codée
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
| | - Thomas Hansen
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The, Netherlands
- Department of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ, Amsterdam, The, Netherlands
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Density functional theory study on the reaction mechanism of Ni+-catalysed cyclohexane dehydrogenation. Struct Chem 2022. [DOI: 10.1007/s11224-021-01876-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Savoo N, Rhyman L, Ramasami P. Theoretical study of a derivative of chlorophosphine with aliphatic and aromatic Grignard reagents: S N2@P or the novel S N2@Cl followed by S N2@C? RSC Adv 2022; 12:9130-9138. [PMID: 35424871 PMCID: PMC8985194 DOI: 10.1039/d2ra00258b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 03/15/2022] [Indexed: 11/21/2022] Open
Abstract
The proposed SN2 reactions of a hindered organophosphorus reactant with aliphatic and aromatic nucleophiles [Ye et al., Org. Lett., 2017, 19, 5384–5387] were studied theoretically in order to explain the observed stereochemistry of the products.
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Affiliation(s)
- Nandini Savoo
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
| | - Lydia Rhyman
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
- Centre for Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Doornfontein Campus, Johannesburg 2028, South Africa
| | - Ponnadurai Ramasami
- Computational Chemistry Group, Department of Chemistry, Faculty of Science, University of Mauritius, Réduit 80837, Mauritius
- Centre for Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Doornfontein Campus, Johannesburg 2028, South Africa
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Ribaudo G, Bortoli M, Oselladore E, Ongaro A, Gianoncelli A, Zagotto G, Orian L. Selenoxide Elimination Triggers Enamine Hydrolysis to Primary and Secondary Amines: A Combined Experimental and Theoretical Investigation. Molecules 2021; 26:2770. [PMID: 34066723 PMCID: PMC8125833 DOI: 10.3390/molecules26092770] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 11/18/2022] Open
Abstract
We discuss a novel selenium-based reaction mechanism consisting in a selenoxide elimination-triggered enamine hydrolysis. This one-pot model reaction was studied for a set of substrates. Under oxidative conditions, we observed and characterized the formation of primary and secondary amines as elimination products of such compounds, paving the way for a novel strategy to selectively release bioactive molecules. The underlying mechanism was investigated using NMR, mass spectrometry and density functional theory (DFT).
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Affiliation(s)
- Giovanni Ribaudo
- Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.R.); (E.O.); (A.O.); (A.G.)
| | - Marco Bortoli
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy;
- Departament de Química, Institut de Química Computacional i Catàlisi, Universitat de Girona, C/M.A. Capmany 69, 17003 Girona, Spain
| | - Erika Oselladore
- Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.R.); (E.O.); (A.O.); (A.G.)
| | - Alberto Ongaro
- Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.R.); (E.O.); (A.O.); (A.G.)
| | - Alessandra Gianoncelli
- Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia, Viale Europa 11, 25123 Brescia, Italy; (G.R.); (E.O.); (A.O.); (A.G.)
| | - Giuseppe Zagotto
- Dipartimento di Scienze del Farmaco, Università degli Studi di Padova, Via Marzolo 5, 35131 Padova, Italy;
| | - Laura Orian
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo 1, 35131 Padova, Italy;
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