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Zafar M, Subramaniyan V, Tibika F, Tulchinsky Y. Cationic ligands - from monodentate to pincer systems. Chem Commun (Camb) 2024; 60:9871-9906. [PMID: 38920056 DOI: 10.1039/d4cc01489h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
For a long time, the small group of cationic ligands stood out as obscure systems within the general landscape of coordinative chemistry. However, this situation has started to change rapidly during the last decade, with more and more examples of metal-coordinated cationic species being reported. The growing interest in these systems is not only of purely academic nature, but also driven by accumulating evidence of their high catalytic utility. Overcoming the inherently poor coordinating ability of cationic species often required additional structural stabilization. In numerous cases this was realized by functionalizing them with a pair of chelating side-arms, effectively constructing a pincer-type scaffold. This comprehensive review aims to encompass all cationic ligands possessing such pincer architecture reported to date. Herein every cationic species that has ever been embedded in a pincer framework is described in terms of its electronic structure, followed by an in-depth discussion of its donor/acceptor properties, based on computational studies (DFT) and available experimental data (IR, NMR or CV). We then elaborate on how the positive charge of these ligands affects the spectroscopic and redox properties, as well as the reactivity, of their complexes, compared to those of the structurally related neutral ligands. Among other systems discussed, this review also surveys our own contribution to this field, namely, the introduction of sulfonium-based pincer ligands and their complexes, recently reported by our group.
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Affiliation(s)
- Mohammad Zafar
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | | | - Françoise Tibika
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | - Yuri Tulchinsky
- Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
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2
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Rana SS, Choudhury J. Unveiling N-Fused Nitreniums as Potent Catalytic Photooxidants. J Am Chem Soc 2024; 146:3603-3608. [PMID: 38293737 DOI: 10.1021/jacs.3c12606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
The first example of a hitherto-unknown facet of catalytic photooxidant capability of nitrenium cations is reported herein. The fundamental limitation of inability of the traditional and reported nitreniums to achieve the excited-state redox potential beyond +2.0 V (vs Ag/AgCl), the primary requirement for a powerful photooxidant, is addressed in this work by developing a structurally unique class of N-fused nitrenium cations, with the required structural engineering involving extensive π-conjugation through ring fusion at the nitrenium site, which enabled significant lowering of the LUMO energy and easy reduction at the excited state (excited-state redox potential up to +2.5 V vs Ag/AgCl), facilitated by effective delocalization/stabilization of the generated radical. This finding opens a new way to discover novel and useful (photo)catalytic properties of nitrenium cations beyond just Lewis acidity.
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Affiliation(s)
- Samim Sohel Rana
- Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India
| | - Joyanta Choudhury
- Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India
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Avigdori I, Singh K, Fridman N, Gandelman M. Nitrenium ions as new versatile reagents for electrophilic amination. Chem Sci 2023; 14:12034-12040. [PMID: 37969608 PMCID: PMC10631241 DOI: 10.1039/d3sc04268e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 09/25/2023] [Indexed: 11/17/2023] Open
Abstract
Herein we report the utilization of N-heterocyclic nitrenium ions - easily prepared, bench-stable and non-oxidating nitrogen sources for the efficient electrophilic amination of aliphatic and aromatic organometallic nucleophiles, towards the facile and general preparation of primary amines. To this end, a plethora of abundant organolithium and organomagnesium reagents were combined with nitrenium salts to generate a variety of previously unexplored N-alkyl and N-aryl triazanes. Through the simple hydrogenolysis of these relatively stable triazanes, we have prepared a diverse scope of primary amines, including linear and branched aliphatic as well as (hetero)aromatic amines possessing various stereo-electronic substituents. Furthermore, we present the facile synthesis of valuable 15N-labelled primary amines from easily prepared 15N-labelled nitrenium salts, as well as a one-pot approach to biologically relevant primary amines. Finally, a recyclable variant of the nitrenium precursor was prepared and a simple recovery protocol was developed to improve the atom-economy of this procedure.
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Affiliation(s)
- Idan Avigdori
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Kuldeep Singh
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology Technion City Haifa 32000 Israel
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4
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Koronatov A, Mauda A, Tumansky B, Kaushansky A, Fridman N, Bravo-Zhivotovskii D, Gandelman M. Multimodal Reactivity of N-H Bonds in Triazanes and Isolation of a Triazinyl Radical. J Am Chem Soc 2022; 144:23642-23648. [PMID: 36525645 DOI: 10.1021/jacs.2c11113] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The employment of nitrogen Lewis acids based on nitrenium cations has been increasingly featured in the fields of main group chemistry and catalysis. A formally reduced form of nitrenium D─cyclic triazanes E─are intriguing chemical compounds, the chemistry of which is completely unexplored. In this work, we reveal that N-H-triazanes exhibit unusual N-H bond properties; namely, they can serve as protons, hydrides, or hydrogen atom donors. This unique multimodal reactivity provides an N-cation, N-anion, or N-radical from the same species. It allowed us to isolate, for the first time, a stable naphto[1,2,3]triazinyl radical, which was fully characterized both computationally and experimentally, including its monomeric X-ray structure. Moreover, this radical can be prepared directly from the nitrenium cation by a single electron reduction (E = -0.46 V), and this process is reversible. We envision versatile uses of this radical in synthetic and materials chemistry.
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Affiliation(s)
- Aleksandr Koronatov
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Assaf Mauda
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Boris Tumansky
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Alexander Kaushansky
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Dmitry Bravo-Zhivotovskii
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion─Israel Institute of Technology, Technion City, Haifa 32000, Israel
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5
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Chen KQ, Zhang BB, Wang ZX, Chen XY. N-Heterocyclic Nitreniums Can Be Employed as Photoredox Catalysts for the Single-Electron Reduction of Aryl Halides. Org Lett 2022; 24:4598-4602. [PMID: 35709368 DOI: 10.1021/acs.orglett.2c01702] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
N-Heterocyclic nitrenium (NHN) salts, the analogues of N-heterocyclic carbenes, have attracted considerable interest. However, relatively little is known about their catalytic ability beyond their Lewis acid catalysis. Herein, we describe that NHNs can serve as catalytic electron acceptors for charge transfer complex photoactivations. We showcase that, under blue light irradiation, the NHN salts could catalyze the generation of aryl radicals from aryl halides.
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Affiliation(s)
- Kun-Quan Chen
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bei-Bei Zhang
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhi-Xiang Wang
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiang-Yu Chen
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
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6
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Ranolia D, Avigdori I, Singh K, Koronatov A, Fridman N, Gandelman M. Triazolium Salts as Lewis Acid Catalysts. Org Lett 2022; 24:3915-3919. [PMID: 35617625 DOI: 10.1021/acs.orglett.2c01108] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe a new type of nitrenium-based Lewis acids: tetraaryl-1,2,3-triazolium salts. These were fully characterized by NMR and X-ray crystallography. The Gutmann-Beckett acidity numbers were determined to be up to 35.6, which is high compared to those of previously studied nitrenium salts. These salts catalyze the facile hydrosilylation-deoxygenation of ketones, aldehydes, acetals, alcohols, ethers, and silyl ethers under mild conditions in excellent yields. To our knowledge, this represents a first example of triazolium ions used as Lewis acid catalysts.
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Affiliation(s)
- Deepak Ranolia
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Idan Avigdori
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Kuldeep Singh
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Aleksandr Koronatov
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
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7
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Singh K, Avigdori I, Kaushansky A, Fridman N, Toledano D, Gandelman M. New Generation of Nitrenium Salts: Catalytic Hydrosilylation of Imines and a Mechanism of Action of Nitrogen Lewis Acids. ACS Catal 2022. [DOI: 10.1021/acscatal.2c01297] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kuldeep Singh
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Idan Avigdori
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Alexander Kaushansky
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Dor Toledano
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion − Israel Institute of Technology, Technion City, Haifa 32000, Israel
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8
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Zhang ZF, Su MD. Theoretical investigations in the reactions of group 15 analogues of the monocationic five-membered N-heterocyclic carbenes: interplay of electrophilicity, basicity, and aromaticity governing the reactivity. NEW J CHEM 2022. [DOI: 10.1039/d1nj04631d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The nature of the group 15 analogs of the five-membered N-heterocyclic carbenes (G15-Rea; G15 = N, P, As, Sb, and Bi) was investigated by using various methodologies.
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Affiliation(s)
- Zheng-Feng Zhang
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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9
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Wei W, Liu Z, Wei R, Liang C, Feng XZ, Han GC. Synthesis, crystal structure and anticorrosion performance of Zn(II) and Ni(II) complexes. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2020.129452] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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10
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Avigdori I, Pogoreltsev A, Kaushanski A, Fridman N, Gandelman M. Frustrated Lewis Pairs Comprising Nitrogen Lewis Acids for Si–H Bond Activation. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202008798] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Idan Avigdori
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Alla Pogoreltsev
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Alexander Kaushanski
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
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11
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Avigdori I, Pogoreltsev A, Kaushanski A, Fridman N, Gandelman M. Frustrated Lewis Pairs Comprising Nitrogen Lewis Acids for Si–H Bond Activation. Angew Chem Int Ed Engl 2020; 59:23476-23479. [DOI: 10.1002/anie.202008798] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/05/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Idan Avigdori
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Alla Pogoreltsev
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Alexander Kaushanski
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry Technion—Israel Institute of Technology Technion City Haifa 32000 Israel
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12
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Srungavruksham NK, Liu YH, Tsai MK, Chiu CW. PSb +P Ligand: Platform for a Stibenium to Transition-Metal Interaction. Inorg Chem 2020; 59:4468-4474. [PMID: 32193926 DOI: 10.1021/acs.inorgchem.9b03530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The coordination chemistry of cationic divalent pnictogen ligands, such as nitrenium and phosphenium, has been well-explored in recent years. However, corresponding studies of a heavier congener, stibenium ion, are rare. To better facilitate a Sb+-metal interaction, a tridentate P-Sb+-P ligand with two phosphine buttresses was designed and synthesized, and its coordination chemistry toward late transition metals was investigated. The stibenium ligand was delivered as an activated P(SbCl)P-AgOTf complex (2) that releases AgCl and the P-Sb+-P ligand upon the treatment with transition metals. Reacting 2 with Rh(I) and Ir(I) metals yielded the anticipated stibenium-transition-metal complexes [(Rh(COD)Cl)2(μ-PSb+P)] OTf ([3][OTf]) and [(Ir(COD)Cl)2(μ-PSb+P)] OTf ([4][OTf]). The M-Sb+-M bridging structure was confirmed by single-crystal X-ray crystallography, and the bonding situation was examined computationally. Theoretical studies revealed the presence of three-center delocalized M-Sb+-M bonding interactions in [3][OTf] and [4][OTf].
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Affiliation(s)
| | - Yi-Hung Liu
- Department of Chemistry, National Taiwan University, No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
| | - Ming-Kang Tsai
- Department of Chemistry, National Taiwan Normal University, No. 88, Section 4, Ting-Zhou Road, Taipei 11677, Taiwan
| | - Ching-Wen Chiu
- Department of Chemistry, National Taiwan University, No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan
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Hassin A, Fridman N, Gandelman M. Bidentate Triazolate-Based Ligand System: Synthesis, Coordination Modes, and Cooperative Bond Activation. Organometallics 2020. [DOI: 10.1021/acs.organomet.9b00775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Asaf Hassin
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Natalia Fridman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Mark Gandelman
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
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