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Gentner T, Ballmann GM, Banerjee S, Kennedy AR, Robertson SD, Mulvey RE. Application of Bis(amido)alkyl Magnesiates toward the Synthesis of Molecular Rubidium and Cesium Hydrido-magnesiates. Organometallics 2024; 43:1393-1401. [PMID: 38938897 PMCID: PMC11200325 DOI: 10.1021/acs.organomet.4c00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/29/2024]
Abstract
Rubidium and cesium are the least studied naturally occurring s-block metals in organometallic chemistry but are in plentiful supply from a sustainability viewpoint as highlighted in the periodic table of natural elements published by the European Chemical Society. This underdevelopment reflects the phenomenal success of organometallic compounds of lithium, sodium, and potassium, but interest in heavier congeners has started to grow. Here, the synthesis and structures of rubidium and cesium bis(amido)alkyl magnesiates [(AM)MgN'2alkyl]∞, where N' is the simple heteroamide -N(SiMe3)(Dipp), and alkyl is nBu or CH2SiMe3, are reported. More stable than their nBu analogues, the reactivities of the CH2SiMe3 magnesiates toward 1,4-cyclohexadiene are revealed. Though both reactions produce target hydrido-magnesiates [(AM)MgN'2H]2 in crystalline form amenable to X-ray diffraction study, the cesium compound could only be formed in a trace quantity. These studies showed that the bulk of the -N(SiMe3)(Dipp) ligand was sufficient to restrict both compounds to dimeric structures. Bearing some resemblance to inverse crown complexes, each structure has [(AM)(N)(Mg)(N)]2 ring cores but differ in having no AM-N bonds, instead Rb and Cs complete the rings by engaging in multihapto interactions with Dipp π-clouds. Moreover, their hydride ions occupy μ3-(AM)2Mg environments, compared to μ2-Mg2 environments in inverse crowns.
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Affiliation(s)
- Thomas
X. Gentner
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Gerd M. Ballmann
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Sumanta Banerjee
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Alan R. Kennedy
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Stuart D. Robertson
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
| | - Robert E. Mulvey
- WestCHEM, Department of Pure
and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, U.K.
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Sreedharan R, Gandhi T. Masters of Mediation: MN(SiMe 3) 2 in Functionalization of C(sp 3)-H Latent Nucleophiles. Chemistry 2024; 30:e202400435. [PMID: 38497321 DOI: 10.1002/chem.202400435] [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: 01/31/2024] [Revised: 03/16/2024] [Accepted: 03/18/2024] [Indexed: 03/19/2024]
Abstract
Organoalkali compounds have undergone a far-reaching transformation being a coupling partner to a mediator in unusual organic conversions which finds its spot in the field of sustainable synthesis. Transition-metal catalysis has always been the priority in C(sp3)-H bond functionalization, however alternatively, in recent times this has been seriously challenged by earth-abundant alkali metals and their complexes arriving at new sustainable organometallic reagents. In this line, the importance of MN(SiMe3)2 (M=Li, Na, K & Cs) reagent revived in C(sp3)-H bond functionalization over recent years in organic synthesis is showcased in this minireview. MN(SiMe3)2 reagent with higher reactivity, enhanced stability, and bespoke cation-π interaction have shown eye-opening mediated processes such as C(sp3)-C(sp3) cross-coupling, radical-radical cross-coupling, aminobenzylation, annulation, aroylation, and other transformations to utilize readily available petrochemical feedstocks. This article also emphasizes the unusual reactivity of MN(SiMe3)2 reagent in unreactive and robust C-X (X=O, N, F, C) bond cleavage reactions that occurred alongside the C(sp3)-H bond functionalization. Overall, this review encourages the community to exploit the untapped potential of MN(SiMe3)2 reagent and also inspires them to take up this subject to even greater heights.
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Affiliation(s)
- Ramdas Sreedharan
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
| | - Thirumanavelan Gandhi
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
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Lachguar A, Pichugov AV, Neumann T, Dubrawski Z, Camp C. Cooperative activation of carbon-hydrogen bonds by heterobimetallic systems. Dalton Trans 2024; 53:1393-1409. [PMID: 38126396 PMCID: PMC10804807 DOI: 10.1039/d3dt03571a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/24/2023] [Indexed: 12/23/2023]
Abstract
The direct activation of C-H bonds has been a rich and active field of organometallic chemistry for many years. Recently, incredible progress has been made and important mechanistic insights have accelerated research. In particular, the use of heterobimetallic complexes to heterolytically activate C-H bonds across the two metal centers has seen a recent surge in interest. This perspective article aims to orient the reader in this fast moving field, highlight recent progress, give design considerations for further research and provide an optimistic outlook on the future of catalytic C-H functionalization with heterobimetallic complexes.
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Affiliation(s)
- Abdelhak Lachguar
- Université de Lyon, Institut de Chimie de Lyon, Laboratory of Catalysis, Polymerization, Processes & Materials, CP2M UMR 5128 CNRS-UCB Lyon 1-CPE Lyon, 43 Bd du 11 Novembre 1918, F-69616 Villeurbanne, France.
| | - Andrey V Pichugov
- Université de Lyon, Institut de Chimie de Lyon, Laboratory of Catalysis, Polymerization, Processes & Materials, CP2M UMR 5128 CNRS-UCB Lyon 1-CPE Lyon, 43 Bd du 11 Novembre 1918, F-69616 Villeurbanne, France.
| | - Till Neumann
- Université de Lyon, Institut de Chimie de Lyon, Laboratory of Catalysis, Polymerization, Processes & Materials, CP2M UMR 5128 CNRS-UCB Lyon 1-CPE Lyon, 43 Bd du 11 Novembre 1918, F-69616 Villeurbanne, France.
| | - Zachary Dubrawski
- Université de Lyon, Institut de Chimie de Lyon, Laboratory of Catalysis, Polymerization, Processes & Materials, CP2M UMR 5128 CNRS-UCB Lyon 1-CPE Lyon, 43 Bd du 11 Novembre 1918, F-69616 Villeurbanne, France.
| | - Clément Camp
- Université de Lyon, Institut de Chimie de Lyon, Laboratory of Catalysis, Polymerization, Processes & Materials, CP2M UMR 5128 CNRS-UCB Lyon 1-CPE Lyon, 43 Bd du 11 Novembre 1918, F-69616 Villeurbanne, France.
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Banerjee S, Ballmann GM, Evans MJ, O'Reilly A, Kennedy AR, Fulton JR, Coles MP, Mulvey RE. Three Oxidative Addition Routes of Alkali Metal Aluminyls to Dihydridoaluminates and Reactivity with CO 2. Chemistry 2023; 29:e202301849. [PMID: 37429823 DOI: 10.1002/chem.202301849] [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: 06/22/2023] [Revised: 07/08/2023] [Accepted: 07/10/2023] [Indexed: 07/12/2023]
Abstract
Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NONDipp )(H)2 ] (AM=Li, Na, K, Rb, Cs; [NONDipp ]2- =[O(SiMe2 NDipp)2 ]2- ; Dipp=2,6-iPr2 C6 H3 ) starting from the alkali metal aluminyls, AM[Al(NONDipp )]. Direct H2 hydrogenation of the heavier analogues (AM=Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4-cyclohexadiene (1,4-CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM=Li-Cs. A further moderation in conditions was noted for the thermal decomposition of the (silyl)(hydrido)aluminates, AM[Al(NONDipp )(H)(SiH2 Ph)]. Probing the reaction of Cs[Al(NONDipp )] with 1,4-CHD provided access to a novel inverse sandwich complex, [{Cs(Et2 O)}2 {Al(NONDipp )(H)}2 (C6 H6 )], containing the 1,4-dialuminated [C6 H6 ]2- dianion and representing the first time that an intermediate in the commonly utilized oxidation process of 1,4-CHD to benzene has been trapped. The synthetic utility of the newly installed Al-H bonds has been demonstrated by their ability to reduce CO2 under mild conditions to form the bis-formate AM[Al(NONDipp )(O2 CH)2 ] compounds, which exhibit a diverse series of eyecatching bimetallacyclic structures.
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Affiliation(s)
- Sumanta Banerjee
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, G1 1XL, Glasgow, UK
| | - Gerd M Ballmann
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, G1 1XL, Glasgow, UK
| | - Matthew J Evans
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6140, New Zealand
| | - Andrea O'Reilly
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6140, New Zealand
| | - Alan R Kennedy
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, G1 1XL, Glasgow, UK
| | - J Robin Fulton
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6140, New Zealand
| | - Martyn P Coles
- School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6140, New Zealand
| | - Robert E Mulvey
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, G1 1XL, Glasgow, UK
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Structural Characterization of the 1-Metallo-2-t-Butyl-1,2-Dihydropyridyl Rubidium and Caesium Complexes. Polyhedron 2023. [DOI: 10.1016/j.poly.2023.116302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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