1
|
Wang Y, Zhang J, Wang F, Wu L. Titanium-Catalyzed Reaction of Silacyclobutanes with Alkenes: Mimicking the Reactivity and Reversing the Selectivity Towards Late Transition Metals. Angew Chem Int Ed Engl 2024:e202420092. [PMID: 39638775 DOI: 10.1002/anie.202420092] [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: 10/17/2024] [Revised: 12/04/2024] [Accepted: 12/05/2024] [Indexed: 12/07/2024]
Abstract
Transition metal-catalyzed ring opening and expansion reactions of silacyclobutanes (SCBs) constitute an atom- and step-economical strategy to construct value-added silicon-containing chemicals. Despite extensive studies, the reaction of SCBs with simple alkenes has only one precedent. Moreover, most reported reactions of SCBs use late transition metals (Pd, Ni, Rh) as catalysts. By contrast, there are no reports of using early transition metals. Herein, we report the first example, to our knowledge, of early-transition-metal-catalyzed reactions of SCBs using earth's second abundant titanium as a catalyst. Notably, orthogonal selectivity was observed. Selective activation of the relatively inert C(sp3)-Si bond was achieved in the case of benzosilacyclobutenes, a selectivity that has rarely been achieved using other metals. Even for silacyclobutanes with C(sp3)-Si bonds only, our titanium system also shows complementary selectivity towards late transition metals to give distinct products. Thus, structurally varied SCBs and alkenes were reacted in our system to afford structurally diverse silicon-containing products that are otherwise difficult to obtain using other transition metals.
Collapse
Affiliation(s)
- Yaqiong Wang
- State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Jiong Zhang
- State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Fang Wang
- State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Lipeng Wu
- State Key Laboratory of Low Carbon Catalysis and Carbon Dioxide Utilization, State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- College of Material Chemistry and Chemical Engineering, Key Laboratory of Organosilicon Chemistry and Material Technology, Ministry of Education, Hangzhou Normal University, Hangzhou, 311121, P. R. China
| |
Collapse
|
2
|
Jafari MG, Russell JB, Myung H, Kwon S, Carroll PJ, Gau MR, Baik MH, Mindiola DJ. Pnictogen-based vanadacyclobutadiene complexes. Chem Sci 2024; 15:19752-19763. [PMID: 39568904 PMCID: PMC11575583 DOI: 10.1039/d4sc05884d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2024] [Accepted: 10/20/2024] [Indexed: 11/22/2024] Open
Abstract
The reactivity of the V[triple bond, length as m-dash]C t Bu multiple bonds in the complex (dBDI)V[triple bond, length as m-dash]C t Bu(OEt2) (C) (dBDI2- = ArNC(CH3)CHC(CH2)NAr, Ar = 2,6- i Pr2C6H3) with unsaturated substrates such as N[triple bond, length as m-dash]CR (R = Ad or Ph) and P[triple bond, length as m-dash]CAd leads to the formation of rare 3d transition metal compounds featuring α-aza-vanadacyclobutadiene, (dBDI)V(κ2- C , N - t BuCC(R)N) (R = Ad, 1; R = Ph, 2) and β-phospha-vanadacyclobutadiene moieties, (dBDI)V(κ2- C , C - t BuCPCAd) (3). Complexes 1-3 are characterized using multinuclear and multidimensional NMR spectroscopy, including the preparation of the 50% 15N-enriched isotopologue (dBDI)V(κ2- C , N - t BuCC(Ad)15N) (1-15N). Solid-state structural analysis is used to determine the dominant resonance structures of these unique pnictogen-based vanadacyclobutadienes. A systematic comparison with the known vanadacyclobutadiene (dBDI)V(κ2- C , C - t BuCC(H)C t Bu) (4) is also presented. Theoretical investigations into the electronic structure of 2-4 highlight the crucial role of unique V-heteroatom interactions in stabilizing the vanadacyclobutadienes and identify the most dominant resonance structures.
Collapse
Affiliation(s)
- Mehrafshan G Jafari
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - John B Russell
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Hwan Myung
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
| | - Seongyeon Kwon
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| | - Patrick J Carroll
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Michael R Gau
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| | - Mu-Hyun Baik
- Center for Catalytic Hydrocarbon Functionalizations, Institute for Basic Science (IBS) Daejeon 34141 Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
| | - Daniel J Mindiola
- Department of Chemistry, University of Pennsylvania Philadelphia Pennsylvania 19104 USA
| |
Collapse
|
3
|
Wu W, Rajeshkumar T, Hong D, Zhu S, Huang Z, Chai F, Wang W, Yuan Q, Wei Y, Xie Z, Maron L, Wang S. Rare-Earth Metal Complexes Bearing Electrophilic Carbon and Strongly Polarized Metallacyclopropane Moiety: Synthesis and Diverse Reactivity toward Small Molecules. Inorg Chem 2024; 63:18365-18378. [PMID: 39287929 DOI: 10.1021/acs.inorgchem.4c02316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2024]
Abstract
Metallacyclopropanes are highly strained and very reactive organometallics; the rare-earth metal complexes bearing both highly reactive electrophilic carbon and strongly polarized metallacyclopropanes are extremely rare. This type of rare-earth metal complexes (κ2-L)RE(η2-C2B10H10)·(THF)3 [L = 1-(2-N-C5H10NCH2CH2)-3-(2,6-iPr2C6H3N═CH)-C8H4N, RE = Lu(1a), Yb(1b), Er(1c), Y(1d), Dy(1e)] bearing the indol-2-yl electrophilic carbon and carboryne-based strongly polarized metallacyclopropanes have been synthesized. Structures of complexes 1 are further confirmed by single-crystal X-ray diffraction and DFT theoretical calculations. It is found that complexes 1 have remarkable reactivity toward different polar unsaturated small molecules, elemental sulfur, and selenium to provide different products (2-15) through the selective reactions of the RE-Ccage, and RE-C2-ind bonds with the given small molecules, respectively. The reactivities of these complexes are different from those of the reported rare-earth metallacyclopropenes and d-block metal-carborynes.
Collapse
Affiliation(s)
- Weikang Wu
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Thayalan Rajeshkumar
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Dongjing Hong
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Shan Zhu
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Zeming Huang
- Anhui Laboratory of Clean Catalytic Engineering, Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application, College of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui, P. R. China
| | - Fuxiang Chai
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Weigang Wang
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Qingbing Yuan
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Yun Wei
- Key Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241000, Anhui, P. R. China
| | - Zuowei Xie
- Department of Chemistry, The Chinese University of Hong Kong, Shatin NT, Hong Kong 999077, China
| | - Laurent Maron
- LPCNO, CNRS & INSA, Université Paul Sabatier, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Shaowu Wang
- Anhui Laboratory of Clean Catalytic Engineering, Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application, College of Chemical and Environmental Engineering, Anhui Polytechnic University, Wuhu 241000, Anhui, P. R. China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P. R. China
| |
Collapse
|
4
|
Bousrez G, Harakat D, Chevreux S, Déchamps-Olivier I, Jaroschik F. Choosing between Ti(II) and Ti(III): selective reduction of titanocene dichloride by elemental lanthanides. Dalton Trans 2024; 53:15595-15601. [PMID: 39230327 DOI: 10.1039/d4dt02004a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
The reduction of titanocene dichloride Cp2TiCl2 with lanthanide metals has led to the discovery of a surprising lanthanide effect: while with most lanthanides, a divalent [Cp2Ti] equivalent was obtained, the use of samarium or ytterbium only led to the reduction to trivalent [Cp2TiCl]-type complexes, including the structurally characterized heterobimetallic complex [Cp2Ti(μ-Cl)2SmCl2(THF)3]. These results were corroborated by reactivity studies (alkyne coupling and radical reactions), EPR spectroscopy and electrospray mass spectrometry, providing new insights into the reduction chemistry of lanthanide metals.
Collapse
Affiliation(s)
- Guillaume Bousrez
- Université de Reims Champagne Ardenne, CNRS UMR 7312, ICMR, URCATech, 51100 Reims, France
- Department of Biological and Chemical Engineering, Aarhus University, 8000 Aarhus C, Denmark
| | - Dominique Harakat
- Université de Reims Champagne Ardenne, CNRS UMR 7312, ICMR, URCATech, 51100 Reims, France
| | - Sylviane Chevreux
- Université de Reims Champagne Ardenne, CNRS UMR 7312, ICMR, URCATech, 51100 Reims, France
- Institut de Recherche de Chimie Paris, UMR CNRS 8247, Chimie ParisTech, PSL University, 75005 Paris, France
| | | | - Florian Jaroschik
- Université de Reims Champagne Ardenne, CNRS UMR 7312, ICMR, URCATech, 51100 Reims, France
- ICGM, Univ. Montpellier, CNRS, ENSCM, 34090 Montpellier, France.
| |
Collapse
|
5
|
Fritsche P, Geyer L, Czernetzki C, Hierlmeier G. Coordination-induced reductive elimination from a titanium(IV) complex. Chem Commun (Camb) 2024; 60:9030-9033. [PMID: 39046231 DOI: 10.1039/d4cc02500h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
Diamidopyridine-supported titanium dibenzyl complexes undergo coordination-induced C-C reductive elimination upon addition of alkynes and quantitative formation of titanacyclopentadienes. The distinct radical mechanism of this reductive mechanism gives new insights into C-C bond formation with titanium.
Collapse
Affiliation(s)
- Paul Fritsche
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074 Würzburg, Germany.
| | - Lucia Geyer
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074 Würzburg, Germany.
| | - Corinna Czernetzki
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074 Würzburg, Germany.
| | - Gabriele Hierlmeier
- Julius-Maximilians-Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074 Würzburg, Germany.
| |
Collapse
|
6
|
Petrov A, Wellnitz T, Hennersdorf F, Reiß F, Hering-Junghans C. On Haptotropic Rearrangements of Diphosphene and Diarsene Ligands in Titanium Complexes. Chemistry 2024; 30:e202400575. [PMID: 38391154 DOI: 10.1002/chem.202400575] [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: 02/21/2024] [Revised: 02/23/2024] [Accepted: 02/23/2024] [Indexed: 02/24/2024]
Abstract
Dipnictenes of the type RE=ER (E=P, As, Sb, Bi) are the isovalence electronic heavier analogs of alkenes. Although diphosphenes and dipnictenes in general show a variety of binding modes in metal complexes, little is known about haptotropic shift reactions involving these ligands. Herein, we report an unprecedented η2 to η1 rearrangement of the dipnictene ligands in titanocene complexes of the type Cp2Ti(Pn2Ar2) (Pn=P, As; Ar=2,4,6-Me3-C6H2, Mes; 2,6-iPr2-C6H3, Dip; 2,4,6-iPr3-C6H2, Tip), initiated by Lewis basic ligands (L=MeCN, PMe3, AdNC, CO). In the presence of L the dipnictene ligand changes its hapticity from η2 to η1 and complexes of the general form Cp2Ti(L)(Pn2Ar2) with a succinctly different electronic structure are obtained. Electronically, the new complexes are best described as biradicaloids with antiferromagnetically coupled (via a π-bond) [Cp2TiIII]⋅+ and [Pn2Ar2]⋅- fragments. However, the biradical character of these systems is affected by the electronic features of the co-ligand and significantly decreases moving from PMe3/MeCN (σ-donors) to CNAd/CO (σ-donors/π-acceptors).
Collapse
Affiliation(s)
- Andrey Petrov
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 3a, 18059, Rostock, Germany
| | - Tim Wellnitz
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 3a, 18059, Rostock, Germany
- Current address: Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | | | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V., Albert-Einstein-Straße 3a, 18059, Rostock, Germany
| | | |
Collapse
|
7
|
Kim J, Egger DT, Frye CW, Beaumier EP, Tonks IA. Cp 2Ti(II) Mediated Rearrangement of Cyclopropyl Imines. Organometallics 2023; 42:1331-1338. [PMID: 37915831 PMCID: PMC10619969 DOI: 10.1021/acs.organomet.3c00032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Ti-catalyzed oxidative alkyne carboamination with alkenes and azo compounds can yield either α,β-unsaturated imines or cyclopropyl imines through a common azatitanacyclohexene intermediate. Herein, we report the synthesis of a model azatitanacyclohexene complex (3) through the ring-opening of a cyclopropyl imine with Cp2Ti(BTMSA) (BTMSA = bis(trimethylsilyl)acetylene). 3 readily undergoes thermal or reductant-catalyzed ring contraction to an azatitanacyclopentene (4), analogous to the proposed mechanism for forming α,β-unsaturated imines in the catalytic reaction. A cyclopropyl imine or an α,β-unsaturated imine could be liberated via the oxidation of 3 or 4 with azobenzene, respectively, further implicating the role of these metallacycles in the Ti-catalyzed carboamination reaction.
Collapse
Affiliation(s)
- Jaekwan Kim
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Dominic T. Egger
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Connor W. Frye
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Evan P. Beaumier
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Ian A. Tonks
- Department of Chemistry, University of Minnesota–Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
8
|
Rosenthal U. How Serendipity and Chance Can Be Transformed into Knowledge: Examples from 50 Years of Research in Organometallic Chemistry and Homogeneous Catalysis. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Uwe Rosenthal
- Leibniz Institute for Catalysis, University of Rostock Albert-Einstein-Str. 29A, 18059 Rostock, Germany
| |
Collapse
|
9
|
Nuñez Bahena E, Schafer LL. From Stoichiometric to Catalytic E–H Functionalization by Non-Metallocene Zirconium Complexes─Recent Advances and Mechanistic Insights. ACS Catal 2022. [DOI: 10.1021/acscatal.2c04308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Erick Nuñez Bahena
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Laurel L. Schafer
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| |
Collapse
|
10
|
Wang S, Heng Y, Li T, Wang D, Hou G, Zi G, Walter MD. Intrinsic reactivity of [η 5-1,3-(Me 3Si) 2C 5H 3] 2U(η 4-C 4Ph 2) in small molecule activation. Dalton Trans 2022; 51:11072-11085. [PMID: 35796202 DOI: 10.1039/d2dt01730j] [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 uranium metallacyclocumulene, [η5-1,3-(Me3Si)2C5H3]2U(η4-C4Ph2) (3) was isolated from the reaction mixture containing [η5-1,3-(Me3Si)2C5H3]2UCl2 (1), potassium graphite (KC8) and 1,4-diphenylbutadiyne (PhCC-CCPh) in good yield. The reactivity of 3 towards various small organic molecules was evaluated. For example, while complex 3 shows no reactivity towards alkynes and 2,2'-bipyridine, it may deliver the [η5-1,3-(Me3Si)2C5H3]2U(II) fragment in the presence of Ph2E2 (E = S, Se) and Ph3CN3, or react as a nucleophile in the presence of carbodiimides, isothiocyanates, aldehydes, ketones, and pyridine derivatives, forming five-, seven- or nine-membered heterometallacycles. On the contrary, addition of Ph2CS to 3 induces CS bond cleavage yielding the dithiolate complex [η5-1,3-(Me3Si)2C5H3]2U[S2(C12H5Ph5)] (14). In contrast, the closely related, but sterically more encumbered uranium metallacyclocumulene [η5-1,2,4-(Me3Si)3C5H2]2U(η4-C4Ph2) (4) features a more limited reactivity which is restricted to mono- and double insertions with small unsaturated organic molecules such as isothiocyanates, ketones and nitriles.
Collapse
Affiliation(s)
- Shichun Wang
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Yi Heng
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Tongyu Li
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Dongwei Wang
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Guohua Hou
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Guofu Zi
- Department of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Marc D Walter
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
| |
Collapse
|
11
|
Beladi-Mousavi SM, Walder L. Materials and systems for polymer-based Metallocene batteries: Status and challenges. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124658] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
12
|
Valdés H, Germán-Acacio JM, van Koten G, Morales-Morales D. Bimetallic complexes that merge metallocene and pincer-metal building blocks: synthesis, stereochemistry and catalytic reactivity. Dalton Trans 2022; 51:1724-1744. [PMID: 34985477 DOI: 10.1039/d1dt03870b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This perspective is to illustrate the synthesis and applications of bimetallic complexes by merging a metallocene and a (cyclopentadienyl/aryl) pincer metal complex. Four possible ways to merge metallocene and pincer-metal motifs are reported and representative examples are discussed in more detail. These bimetallic complexes have been employed in some important catalytic reactions such as cross-coupling, transfer hydrogenation or synthesis of ammonia. The metallocene fragment may tune the electronic properties of the pincer ligand, due to its redox reversible properties. Also, the presence of two metals in a single complex allows their electronic communication, which proved beneficial for, e.g., the catalytic activity of some species. The presence of the metallocene fragment provides an excellent opportunity to develop chiral catalysts, because the metallocene merger generally renders the two faces of the pincer-metal catalytic site diastereotopic. Besides, an extra chiral functionality may be added to the bimetallic species by using pincer motifs that are planar chiral, e.g. by using the different substituents of pincer ligand "arms" or non-symmetrical arene groupings. Post-functionalization of pre-formed pincer-metal complexes, via η6-coordination with an areneophile such as [CpRu]+ and [Cp*Ru]+ presents a striking strategy to obtain diastereomeric metallocene-pincer type derivatives, that actually involve half-sandwich metallocenes. This approach offers the possibility to create diastereomerically pure derivatives by using the chiral TRISPHAT anion. The authors hope that this report of the synthetic, physico-chemical properties and remarkable catalytic activities of metallocene-based pincer-metal complexes will inspire other researchers to continue exploring this realm.
Collapse
Affiliation(s)
- Hugo Valdés
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus de Montilivi, Girona E-17003, Catalonia, Spain
| | - Juan M Germán-Acacio
- Red de Apoyo a la Investigación, Coordinación de la Investigación Científica-UNAM, Instituto Nacional de Ciencias Médicas y Nutrición SZ, C. P.14000, Ciudad de México, Mexico
| | - Gerard van Koten
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, 3584CG Utrecht, The Netherlands
| | - David Morales-Morales
- Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad Universitaria, Ciudad de México. C. P. 04510, Mexico.
| |
Collapse
|
13
|
Rosenthal U. Take a "Snapshot" of New Syntheses, Reactions, and Characterizations from Unusual Unsaturated Ring Strained Group 4 Metallacycles. Chemistry 2021; 27:17751-17760. [PMID: 34463390 PMCID: PMC9293241 DOI: 10.1002/chem.202102855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Indexed: 11/24/2022]
Abstract
Recently published syntheses, reactions and characterizations of unusual unsaturated ring strained Group 4 metallocene metallacycles like metalla-cyclocumulenes, -cycloallenes and -cycloalkynes with different ring size are updated for the last three years. There exist for some of these metallacycles, depending on the ring size, 7-, 5- and 4-membered compounds. The new results for these metallacycles are summarized here and considered in addition to the former published results. Additionally, several compounds of this type were now characterized by new reactions. For a better understanding of these compounds, some spectroscopical methods as well as theoretical calculations were published. Despite of these all-C-metallacycles, only in some cases the syntheses and reactions for the corresponding hetero-metallacycles were published too. Examples for these metallaheterocyclic compounds will not be considered in this article. All these unusual ring strained compounds have a great potential for a lot of interesting synthetic applications in the future. Additionally, they are very interesting from the theoretical point of view.
Collapse
Affiliation(s)
- Uwe Rosenthal
- Leibniz Institute for CatalysisUniversity of RostockAlbert-Einstein-Str. 29 A18059RostockGermany
| |
Collapse
|
14
|
Shi X, Li S, Reiß M, Spannenberg A, Holtrichter-Rößmann T, Reiß F, Beweries T. 1-Zirconacyclobuta-2,3-dienes: synthesis of organometallic analogs of elusive 1,2-cyclobutadiene, unprecedented intramolecular C-H activation, and reactivity studies. Chem Sci 2021; 12:16074-16084. [PMID: 35024129 PMCID: PMC8672727 DOI: 10.1039/d1sc06052j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/22/2021] [Indexed: 01/25/2023] Open
Abstract
The structure, bonding, and reactivity of small, highly unsaturated ring systems is of fundamental interest for inorganic and organic chemistry. Four-membered metallacyclobuta-2,3-dienes, also referred to as metallacycloallenes, are among the most exotic examples for ring systems as these represent organometallic analogs of 1,2-cyclobutadiene, the smallest cyclic allene. Herein, the synthesis of the first examples of 1-zirconacyclobuta-2,3-dienes of the type [Cp'2Zr(Me3SiC3SiMe3)] (Cp'2 = rac-(ebthi), (ebthi = 1,2-ethylene-1,1'-bis(η5-tetrahydroindenyl)) (2a); rac-Me2Si(thi)2, thi = (η5-tetrahydroindenyl), (2b)) is presented. Both complexes undergo selective thermal C-H activation at the 7-position of the ansa-cyclopentadienyl ligand to produce a new type of "tucked-in" zirconocene system, 3a and 3b, that possesses a η3-propargyl/allenyl ligand. Both types of complexes react with carbonyl compounds, producing enynes in the case of 2a and 2b, as well as η1-allenyl complexes for 3a and 3b. Computational analysis of the structure and bonding of 2a and 3a reveals significant differences to a previously described related Ti complex. All complexes were fully characterised, including X-ray crystallography and experimental results were supported by DFT analysis.
Collapse
Affiliation(s)
- Xinzhe Shi
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Sihan Li
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Melanie Reiß
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | | | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| | - Torsten Beweries
- Leibniz-Institut für Katalyse e.V. Albert-Einstein-Str. 29a 18059 Rostock Germany
| |
Collapse
|
15
|
Rosenthal U. Latest News: Reactions of Group 4 Bis(trimethylsilyl)acetylene Metallocene Complexes and Applications of the Obtained Products. ChemistryOpen 2021; 10:1234-1243. [PMID: 34882978 PMCID: PMC8659550 DOI: 10.1002/open.202100258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 11/23/2021] [Indexed: 11/16/2022] Open
Abstract
Recently published reactions of group 4 metallocene bis(trimethylsilyl)acetylene (btmsa) complexes from the last two years are reviewed. Complexes like Cp'2 Ti(η2 -Me3 SiC2 SiMe3 ) and Cp2 Zr(py)(η2 -Me3 SiC2 SiMe3 ) with Cp' as Cp (cyclopentadienyl) and Cp* (pentamethylcyclopentadienyl) have been considered (py=pyridine). These complexes can liberate a reactive low-valent titanium or zirconium center by dissociation of the ligands and act as ''masked'' MII complexes (M=Ti, Zr). They represent excellent sources for the clean generation of the reactive coordinatively and electronically unsaturated complex fragments [Cp'2 M]. This is the reason why they were used for many synthetic and catalytic reactions during the last years. As an update to several review articles on this topic, this contribution provides an update with recent examples of preparative organometallic and organic chemistry of these complexes, acting as reagents for a wide range of coordinating and coupling reactions. In addition, applications and investigations concerning reaction products derived from this chemistry are mentioned, too.
Collapse
Affiliation(s)
- Uwe Rosenthal
- Leibniz Institute for Catalysis at theUniversity of RostockAlbert-Einstein-Str. 29 A18059RostockGermany
| |
Collapse
|
16
|
Lv ZJ, Liu W, Zhu M, Chai Z, Wei J, Zhang WX. Insertion Chemistry of Lutetacyclopropene toward Unsaturated C-O/C-N Bonds. Chemistry 2021; 27:16498-16504. [PMID: 34608685 DOI: 10.1002/chem.202103065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Indexed: 11/08/2022]
Abstract
Although the reaction chemistry of transition metallacyclopropenes has been well-established in the last decades, the reactivity of rare-earth metallacyclopropenes remains elusive. Herein, we report the reaction of lutetacyclopropene 1 toward a series of unsaturated molecules. The reaction of 1 with one equiv. of PhCOMe, Ar1 CHO (Ar1 =2,6-Me2 C6 H3 ), W(CO)6 , and PhCH=NPh provided oxalutetacyclopentenes, metallacyclic lutetoxycarbene, and azalutetacyclopentene via 1,2-insertion of C=O, C≡O, or C=N bonds into Lu-Csp2 bond, respectively. However, the reaction between 1 and Ar2 N=C=NAr2 (Ar2 =4-MeC6 H4 ) gave an acyclic lutetium complex with a diamidinate ligand by the coupling of one molecule of 1 with two carbodiimides, irrespective of the amount of carbodiimide employed. More interestingly, when 1 was treated with two equiv. of Ar1 CHO, the reductive coupling of two C=O bonds was discovered to give a lutetium pinacolate complex along with the release of tolan. Remarkably, the reactivity of 1 is significantly different from that of scandacyclopropenes; these metallacycles derived from 1 all represent the first cases in rare-earth organometallic chemistry.
Collapse
Affiliation(s)
- Ze-Jie Lv
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| | - Wei Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| | - Miaomiao Zhu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| | - Zhengqi Chai
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P.R. China
| |
Collapse
|
17
|
Lv ZJ, Zhu M, Liu W, Chai Z, Wei J, Zhang WX. Reactivity of Lutetacyclopropene toward Benzyl, Benzoyl, and Trimethylsilyl Nitriles Affording Diversified Lutetium Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Ze-Jie Lv
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Miaomiao Zhu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wei Liu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Zhengqi Chai
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| |
Collapse
|
18
|
Abstract
Titanium is an attractive metal for catalytic reaction development: it is earth-abundant, inexpensive, and generally nontoxic. However-like most early transition metals-catalytic redox reactions with Ti are difficult because of the stability of the high-valent TiIV state. Understanding the fundamental mechanisms behind Ti redox processes is key for making progress toward potential catalytic applications. This Account details recent progress in Ti-catalyzed (and -mediated) oxidative amination reactions that proceed through formally TiII/TiIV catalytic cycles.This class of reactions is built on our initial discovery of Ti-catalyzed [2 + 2 + 1] pyrrole synthesis from alkynes and azobenzene, where detailed mechanistic studies have revealed important factors that allow for catalytic turnover despite the inherent difficulty of Ti redox. Two important conclusions from mechanistic studies are that (1) low-valent Ti intermediates in catalysis can be stabilized through coordination of π-acceptor substrates or products, where they can act as "redox-noninnocent" ligands through metal-to-ligand π back-donation, and (2) reductive elimination processes with Ti proceed through π-type electrocyclic (or pericyclic) reaction mechanisms rather than direct σ-bond coupling.The key reactive species in Ti-catalyzed oxidative amination reactions are Ti imidos (Ti≡NR), which can be generated from either aryl diazenes (RN═NR) or organic azides (RN3). These Ti imidos can then undergo [2 + 2] cycloadditions with alkynes, resulting in intermediates that can be coupled to an array of other unsaturated functional groups, including alkynes, alkenes, nitriles, and nitrosos. This basic reactivity pattern has been extended into a broad range of catalytic and stoichiometric oxidative multicomponent coupling reactions of alkynes and other reactive small molecules, leading to multicomponent syntheses of various heterocycles and aminated building blocks.For example, catalytic oxidative coupling of Ti imidos with two different alkynes leads to pyrroles, while stoichiometric oxidative coupling with alkynes and nitriles leads to pyrazoles. These heterocycle syntheses often yield substitution patterns that are complementary to those of classical condensation routes and provide access to new electron-rich, highly substituted heteroaromatic scaffolds. Furthermore, catalytic oxidative alkyne carboamination reactions can be accomplished via reaction of Ti imidos with alkynes and alkenes, yielding α,β-unsaturated imine or cyclopropylimine building blocks. New catalytic and stoichiometric oxidative amination methods such as alkyne α-diimination, isocyanide imination, and ring-opening oxidative amination of strained alkenes are continuously emerging as a result of better mechanistic understanding of Ti redox catalysis.Ultimately, these Ti-catalyzed and -mediated oxidative amination methods demonstrate the importance of examining often-overlooked elements like the early transition metals through the lens of modern catalysis: rather than a lack of utility, these elements frequently have undiscovered potential for new transformations with orthogonal or complementary selectivity to their late transition metal counterparts.
Collapse
Affiliation(s)
- Ian A. Tonks
- Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
19
|
Affiliation(s)
- Ludwig Hackl
- Technische Universität Braunschweig, Institute of Inorganic and Analytical Chemistry, Hagenring 30, 38106 Braunschweig, Germany
| | - Lukas Körner
- Technische Universität Braunschweig, Institute of Inorganic and Analytical Chemistry, Hagenring 30, 38106 Braunschweig, Germany
| | - Matthias Tamm
- Technische Universität Braunschweig, Institute of Inorganic and Analytical Chemistry, Hagenring 30, 38106 Braunschweig, Germany
| |
Collapse
|
20
|
Lv ZJ, Chai Z, Zhu M, Wei J, Zhang WX. Selective Coupling of Lanthanide Metallacyclopropenes and Nitriles via Azametallacyclopentadiene and η 2-Pyrimidine Metallacycle. J Am Chem Soc 2021; 143:9151-9161. [PMID: 34029479 DOI: 10.1021/jacs.1c03604] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Exploring new lanthanide metallacycles and finding their unique chemistry different from the analogues of transition metals are of great interest and importance. In this work, we reported the synthesis, characterization, and reactivity toward nitriles of two lanthanide metallacyclopropenes: lutetacyclopropene 2a and dysprosacyclopropene 2b. The selective coupling of 2a and three molecules of PhCN was found for the first time to provide the unexpected fused lutetacycle 3a with one 1,6-dihydropyrimidine ring. Mechanistic studies by DFT calculations reveal that the triple insertion of PhCN into 2a proceeds through four key steps: the insertion of the first PhCN into 2a giving azalutetacyclopentadiene IM1, the insertion of the second PhCN into the Lu-N bond of IM1, the intramolecular electrocyclization providing a highly strained η2-pyrimidine metallacycle, and the insertion of the third PhCN into the Lu-Csp3 bond. Isolation and characterization of two active intermediates, azalutetacyclopentadiene IM1 and η2-pyrimidine dysprosacycle, provide critical evidence for the formation of 3a. Furthermore, IM1 was also reported to react with TMSCN, isocyanides, or W(CO)6 to furnish the fused [4,5] lutetacycles. The chemistry of two lanthanide metallacyclopropenes with nitriles is significantly different from these metallacyclopropenes of scandium and other metals. Most notably, the azalutetacyclopentadienes, η2-pyrimidine complex, and other metallacycles all represent the first examples in rare-earth organometallic chemistry; the formation of these new lutetacycles provides concrete evidence for understanding the mechanism of transition metal promoted or catalyzed [2+2+2] cycloaddition between alkynes and nitriles.
Collapse
Affiliation(s)
- Ze-Jie Lv
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Zhengqi Chai
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Miaomiao Zhu
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Junnian Wei
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| | - Wen-Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), State Key Laboratory of Rare Earth Materials Chemistry and Applications & Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing 100871, China
| |
Collapse
|
21
|
Abstract
The f-block chemistry of phospholyl and arsolyl ligands, heavier p-block analogues of substituted cyclopentadienyls (CpR , C5 R5 ) where one or more CR groups are replaced by P or As atoms, is less developed than for lighter isoelectronic C5 R5 rings. Heterocyclopentadienyl complexes can exhibit properties that complement and contrast with CpR chemistry. Given that there has been renewed interest in phospholyl and arsolyl f-block chemistry in the last two decades, coinciding with a renaissance in f-block solution chemistry, a review of this field is timely. Here, the syntheses of all structurally characterised examples of lanthanide and actinide phospholyl and arsolyl complexes to date are covered, including benzannulated derivatives, and together with group 3 complexes for completeness. The physicochemical properties of these complexes are reviewed, with the intention of motivating further research in this field.
Collapse
Affiliation(s)
- David P Mills
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M139PL, UK
| | - Peter Evans
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M139PL, UK
| |
Collapse
|
22
|
Wang D, Ding W, Hou G, Zi G, Walter MD. Uranium versus Thorium: Synthesis and Reactivity of [η 5 -1,2,4-(Me 3 C) 3 C 5 H 2 ] 2 U[η 2 -C 2 Ph 2 ]. Chemistry 2021; 27:6767-6782. [PMID: 33559922 PMCID: PMC8251885 DOI: 10.1002/chem.202100089] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Indexed: 01/09/2023]
Abstract
The synthesis, electronic structure, and reactivity of a uranium metallacyclopropene were comprehensively studied. Addition of diphenylacetylene (PhC≡CPh) to the uranium phosphinidene metallocene [η5 -1,2,4-(Me3 C)3 C5 H2 ]2 U=P-2,4,6-tBu3 C6 H2 (1) yields the stable uranium metallacyclopropene, [η5 -1,2,4-(Me3 C)3 C5 H2 ]2 U[η2 -C2 Ph2 ] (2). Based on density functional theory (DFT) results the 5f orbital contributions to the bonding within the metallacyclopropene U-(η2 -C=C) moiety increases significantly compared to the related ThIV compound [η5 -1,2,4-(Me3 C)3 C5 H2 ]2 Th[η2 -C2 Ph2 ], which also results in more covalent bonds between the [η5 -1,2,4-(Me3 C)3 C5 H2 ]2 U2+ and [η2 -C2 Ph2 ]2- fragments. Although the thorium and uranium complexes are structurally closely related, different reaction patterns are therefore observed. For example, 2 reacts as a masked synthon for the low-valent uranium(II) metallocene [η5 -1,2,4-(Me3 C)3 C5 H2 ]2 UII when reacted with Ph2 E2 (E=S, Se), alkynes and a variety of hetero-unsaturated molecules such as imines, ketazine, bipy, nitriles, organic azides, and azo derivatives. In contrast, five-membered metallaheterocycles are accessible when 2 is treated with isothiocyanate, aldehydes, and ketones.
Collapse
Affiliation(s)
- Deqiang Wang
- Department of ChemistryBeijing Normal UniversityBeijing100875China
| | - Wanjian Ding
- Department of ChemistryBeijing Normal UniversityBeijing100875China
| | - Guohua Hou
- Department of ChemistryBeijing Normal UniversityBeijing100875China
| | - Guofu Zi
- Department of ChemistryBeijing Normal UniversityBeijing100875China
| | - Marc D. Walter
- Institut für Anorganische und Analytische ChemieTechnische Universität BraunschweigHagenring 3038106BraunschweigGermany
| |
Collapse
|
23
|
Fischer M, Reiß F, Hering-Junghans C. Titanocene pnictinidene complexes. Chem Commun (Camb) 2021; 57:5626-5629. [PMID: 33989372 DOI: 10.1039/d1cc01305j] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The phospha-Wittig reagent MesTerPPMe3 (MesTer = 2,6-{2,4,6-Me3-C6H2}-C6H3) and arsa-Wittig reagent DipTerAsPMe3 (DipTer = 2,6-{2,6-iPr2-C6H3}-C6H3) have been employed to synthesize the titanocene complexes Cp2Ti(PMe3)PnAr (Pn = P, As) with terminal phosphinidene or arsinidene ligands, respectively. Ab initio studies show that the description as singlet biradicaloids in their ground state is warranted.
Collapse
Affiliation(s)
- Malte Fischer
- Leibniz-Institut für Katalyse e.V. (LIKAT Rostock), Albert-Einstein-Straße 29a, Rostock 18059, Germany.
| | - Fabian Reiß
- Leibniz-Institut für Katalyse e.V. (LIKAT Rostock), Albert-Einstein-Straße 29a, Rostock 18059, Germany.
| | - Christian Hering-Junghans
- Leibniz-Institut für Katalyse e.V. (LIKAT Rostock), Albert-Einstein-Straße 29a, Rostock 18059, Germany.
| |
Collapse
|