51
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Seo S, Yu X, Marks TJ. Intramolecular Hydroalkoxylation/Cyclization of Alkynyl Alcohols Mediated by Lanthanide Catalysts. Scope and Reaction Mechanism. J Am Chem Soc 2008; 131:263-76. [DOI: 10.1021/ja8072462] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- SungYong Seo
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Xianghua Yu
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Tobin J. Marks
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208
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52
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Zhang WX, Nishiura M, Hou Z. Synthesis of (Z)-1-Aza-1,3-enynes by the Cross-Coupling of Terminal Alkynes with Isocyanides Catalyzed by Rare-Earth Metal Complexes. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200804306] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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53
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LIU YY, WANG SW, ZHANG LJ, WU YJ, LI QH, YANG GS, XIE MH. Simple Lanthanide Amides [(Me3Si)2N]3Ln(µ-Cl)Li(THF)3as Highly Efficient Catalysts for the Nitroaldol Reaction. CHINESE J CHEM 2008. [DOI: 10.1002/cjoc.200890402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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54
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Zhang WX, Nishiura M, Hou Z. Synthesis of (Z)-1-Aza-1,3-enynes by the Cross-Coupling of Terminal Alkynes with Isocyanides Catalyzed by Rare-Earth Metal Complexes. Angew Chem Int Ed Engl 2008; 47:9700-3. [DOI: 10.1002/anie.200804306] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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55
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Lynam JM, Nixon TD, Whitwood AC. Solvent and phosphine dependency in the reaction of cis-RuCl2(P–P)2 (P–P=dppm or dppe) with terminal alkynes. J Organomet Chem 2008. [DOI: 10.1016/j.jorganchem.2008.06.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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56
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Panda TK, Hrib CG, Jones PG, Jenter J, Roesky PW, Tamm M. Rare Earth and Alkaline Earth Metal Complexes with Me2Si-Bridged Cyclopentadienyl-Imidazolin-2-Imine Ligands and Their Use as Constrained-Geometry Hydroamination Catalysts. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800606] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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57
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Randoll S, Jones PG, Tamm M. Chromium Complexes with Me2Si-Bridged Cyclopentadienyl-imidazolin-2-imine Ligands: Synthesis, Structure, and Use in Ethylene Polymerization Catalysis. Organometallics 2008. [DOI: 10.1021/om800145z] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Sören Randoll
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina zu Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany
| | - Peter G. Jones
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina zu Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany
| | - Matthias Tamm
- Institut für Anorganische and Analytische Chemie, Technische Universität Carolo-Wilhelmina zu Braunschweig, Hagenring 30, D-38106 Braunschweig, Germany
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58
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Pasquini C, Fratoddi I, Capitani D, Mannina L, Bassetti M. One-step synthesis of low molecular weight poly(p-phenyleneethynylenevinylene)s via polyaddition of aromatic diynes by catalysis of the [Ru(p-cymene)Cl2]2/AcOH system. J Org Chem 2008; 73:3892-9. [PMID: 18410147 DOI: 10.1021/jo800471p] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
pi-Conjugated low molecular weight polymers characterized by regio- and stereoregular alternation of phenylene and ( E)-1-en-3-yne moieties have been synthesized by polyaddition of 1,4-diethynylbenzene or of 2,5-diethynyl-1,4-alkoxybenzene monomers, employing the commercially available di-micro-chlorobis[( p-cymene)chlororuthenium(II)] complex as the metal catalyst source, under homogeneous, atom-economical, amine- and phosphine-free conditions. Bulk materials of poly( p-phenyleneethynylenevinylene) derivatives are obtained with yields larger than 80%, from which polymers readily soluble in chlorinated solvents and in tetrahydrofuran are extracted in 60-75% yields. The polymers with average degrees of polymerization in the range n AV = 4-8 display optical properties in solution similar to those of the higher molecular weights analogues.
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Affiliation(s)
- Chiara Pasquini
- CNR, Istituto di Metodologie Chimiche, Sezione Meccanismi di Reazione, and Dipartimento di Chimica, Università degli Studi di Roma La Sapienza, Roma, Italy
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59
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Zhang WX, Nishiura M, Mashiko T, Hou Z. Half-Sandwicho-N,N-Dimethylaminobenzyl Complexes over the Full Size Range of Group 3 and Lanthanide Metals. Synthesis, Structural Characterization, and Catalysis of Phosphine PH Bond Addition to Carbodiimides. Chemistry 2008; 14:2167-79. [DOI: 10.1002/chem.200701300] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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60
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Ciclosi M, Estevan F, Lahuerta P, Passarelli V, Pérez-Prieto J, Sanaú M. An Unprecedented Iridium(III) Catalyst for Stereoselective Dimerisation of Terminal Alkynes. Adv Synth Catal 2008. [DOI: 10.1002/adsc.200700406] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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61
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Shen Q, Huang W, Wang J, Zhou X. Ln[N(SiMe3)2]3/RNH2 Catalyzed Monoaddition of Terminal Alkynes to Nitriles: A Novel and Concise Access to the Synthesis of Ynones. Organometallics 2008. [DOI: 10.1021/om700891k] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Quansheng Shen
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People’s Republic of China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
| | - Wen Huang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People’s Republic of China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
| | - Jialiang Wang
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People’s Republic of China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
| | - Xigeng Zhou
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People’s Republic of China, and State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, People’s Republic of China
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62
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Zhang WX, Hou Z. Catalytic addition of alkyne C–H, amine N–H, and phosphine P–H bonds to carbodiimides: an efficient route to propiolamidines, guanidines, and phosphaguanidines. Org Biomol Chem 2008; 6:1720-30. [DOI: 10.1039/b800135a] [Citation(s) in RCA: 139] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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63
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Nishimura T, Guo XX, Ohnishi K, Hayashi T. Rhodium-Catalyzed Hydroalkynylation of Internal Alkynes with Silylacetylenes: An Alkynylrhodium(I) Intermediate Generated from the Hydroxorhodium(I) Complex [Rh(OH)(binap)]2. Adv Synth Catal 2007. [DOI: 10.1002/adsc.200700334] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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64
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Ge S, Norambuena VFQ, Hessen B. Highly Efficient Regio- and Stereoselective Dimerization of (Hetero)aromatic Terminal Alkynes by Organo Rare-Earth Metal Catalysts. Organometallics 2007. [DOI: 10.1021/om700893f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shaozhong Ge
- Center for Catalytic Olefin Polymerization, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Victor F. Quiroga Norambuena
- Center for Catalytic Olefin Polymerization, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Bart Hessen
- Center for Catalytic Olefin Polymerization, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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65
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Bassetti M, Pasquini C, Raneri A, Rosato D. Selective Dimerization of Arylalkynes to (E)-1,4-Diaryl Enynes Catalyzed by the [Ru(p-cymene)Cl2]2/Acetic Acid System under Phosphine-Free Conditions. J Org Chem 2007; 72:4558-61. [PMID: 17497925 DOI: 10.1021/jo0702692] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The commercially available di-mu-chlorobis[(p-cymene)chlororuthenium(II)] complex catalyzes the dimerization of aromatic alkynes in acetic acid at room temperature to form the corresponding (E)-1,4-diarylbut-1-ene-3-yne derivatives, with high stereoselectivity. The procedure does not require the use of additives and can be carried out in the presence of water or aprotic cosolvents, under homogeneous conditions.
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Affiliation(s)
- Mauro Bassetti
- CNR, Istituto di Metodologie Chimiche, Dipartimento di Progettazione Molecolare, Università La Sapienza, 00185 Roma, Italy.
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66
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Ghosh R, Zhang X, Achord P, Emge TJ, Krogh-Jespersen K, Goldman AS. Dimerization of Alkynes Promoted by a Pincer-Ligated Iridium Complex. C−C Reductive Elimination Inhibited by Steric Crowding. J Am Chem Soc 2007; 129:853-66. [PMID: 17243822 DOI: 10.1021/ja0647194] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pincer-ligated species (PCP)Ir (PCP = kappa3-C6H3-2,6-(CH2PtBu2)2) is found to promote dimerization of phenylacetylene to give the enyne complex (PCP)Ir(trans-1,4-phenyl-but-3-ene-1-yne). The mechanism of this reaction is found to proceed through three steps: (i) addition of the alkynyl C-H bond to iridium, (ii) insertion of a second phenylacetylene molecule into the resulting Ir-H bond, and (iii) vinyl-acetylide reductive elimination. Each of these steps has been investigated, by both experimental and computational (DFT) methods, to yield unexpected conclusions of general interest. (i) The product of alkynyl C-H addition, (PCP)Ir(CCPh)(H) (3), has been isolated and, in accord with experimental observations, is calculated to be 29 kcal/mol more stable than the analogous product of benzene C-H addition. (ii) Insertion of a second PhCCH molecule into the Ir-H bond of 3 proceeds rapidly, but with a 1,2-orientation. This orientation gives (PCP)Ir(CCPh)(CPh=CH2) (4) which would yield the 1,3-diphenyl-enyne if it were to undergo C-C elimination; however, the insertion is reversible, which represents the first example, to our knowledge, of simple beta-H elimination from a vinyl group to give a terminal hydride. The 2,1-insertion product (PCP)Ir(CCPh)(CH=CHPh) (6) forms more slowly, but unlike the 1,2 insertion product it undergoes C-C elimination to give the observed enyne. (iii) The failure of 4 to undergo C-C elimination is found to be general for (PCP)Ir(CCPh)(vinyl) complexes in which the vinyl group has an alpha-substituent. Thus, although C-C elimination relieves crowding, the reaction is inhibited by increased crowding. Density-functional theory (DFT) calculations support this surprising conclusion and offer a clear explanation. Alkynyl-vinyl bond formation in the C-C elimination transition state involves the vinyl group pi-system; this requires that the vinyl group must rotate (around the Ir-C bond) by ca. 90 degrees to achieve an appropriate orientation. This rotation is severely inhibited by steric crowding, particularly when the vinyl group bears an alpha-substituent.
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Affiliation(s)
- Rajshekhar Ghosh
- Department of Chemistry and Chemical Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA
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67
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68
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Paolucci G, Vignola M, Zanella A, Bertolasi V, Polo E, Sostero S. Substituted Ring‐Fused Yttrium Derivatives – X‐ray Crystal Structures of [(L′YCl
2
·THF)
2
LiCl·2THF] and [{L′YCl(OH)}
6
·2THF] (L′ = 2‐Phenyl‐4,5,6,7,8‐hexahydroazulenyl). Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600399] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Gino Paolucci
- Dipartimento di Chimica, Università Ca’Foscari di Venezia, Dorsoduro 2137, 30123 Venezia, Italy
| | - Manuela Vignola
- Dipartimento di Chimica, Università Ca’Foscari di Venezia, Dorsoduro 2137, 30123 Venezia, Italy
| | - Alessandra Zanella
- Dipartimento di Chimica, Università Ca’Foscari di Venezia, Dorsoduro 2137, 30123 Venezia, Italy
| | - Valerio Bertolasi
- Centro di Strutturistica Diffrattometrica and Dipartimento di Chimica, Università di Ferrara, 44100 Ferrara, Italy, Fax: +39‐053‐224‐0709
| | - Eleonora Polo
- C.N.R.I.S.O.F., sez. Ferrara, Dipartimento di Chimica, Università di Ferrara, Ferrara, Italy, Fax: +39‐053‐224‐0709
| | - Silvana Sostero
- C.N.R.I.S.O.F., sez. Ferrara, Dipartimento di Chimica, Università di Ferrara, Ferrara, Italy, Fax: +39‐053‐224‐0709
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69
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Robert D, Trifonov AA, Voth P, Okuda J. “Constrained geometry” catalysts of the rare-earth metals for the hydrosilylation of olefins. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2006.01.060] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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70
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Liu R, Zhang C, Zhu Z, Luo J, Zhou X, Weng L. Reactivity of Lanthanocene Amide Complexes toward Ketenes: Unprecedented Organolanthanide-Induced Conjugate Electrophilic Addition of Ketenes to Arenes. Chemistry 2006; 12:6940-52. [PMID: 16755619 DOI: 10.1002/chem.200600161] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper presents some unusual types of reactions of lanthanocene amide complexes with ketenes, and demonstrates that these reactions are dependent on the nature of amide ligands and ketenes as well as the stoichiometric ratio under the conditions involved. The reaction of [{Cp(2)LnNiPr(2)}(2)] with four equivalents of Ph(2)CCO in toluene affords the unexpected enolization dearomatization products [Cp(2)Ln(OC{2,5-C(6)H(5)(==CPhCONiPr(2)-4)}==CPh(2))] (Ln = Yb (1 a), Er (1 b)) in good yields, representing an unprecedented conjugate electrophilic addition to a non-coordinated benzenoid nucleus. Treatment of [{Cp(2)LnNiPr(2)}(2)] with four equivalents of PhEtCCO under the same conditions gives the unexpected enolization dearomatization/rearomatization products [{Cp(2)Ln(OC{C(6)H(4)(p-CHEtCONiPr(2))}==CEtPh)}(2)] (Ln = Yb (2 a), Er (2 b), Dy (2 c)). However, reaction of [{Cp(2)YbNiPr(2)}(2)] with PhEtCCO in THF forms only the mono-insertion product [Cp(2)Yb{OC(NiPr(2))==CEtPh}](THF) (3). Hydrolysis of 2 afforded aryl ketone PhEtCHCOC(6)H(4)(p-CHEtCONiPr(2)) (4) and the overall formation of aryl ketone 4 provides an alternative route to the acylation of aromatic compounds. Moreover, reaction of [{Cp(2)LnNHPh}(2)] with excess of PhEtCCO or Ph(2)CCO in toluene affords only the products from a formal insertion of the C==C bond of the ketene into the N--H bond, [(Cp(2)Ln{OC(CHEtPh)NPh})(2)] (Ln = Yb (5 a), Y (5 b)) or [(Cp(2)Er{OC(CHPh(2))NPh})(2)] (6), respectively, indicating that an isomerization involving a 1,3-hydrogen shift occurs more easily than the conjugate electrophilic addition reaction, along with the initial amide attack on the ketene carbonyl carbon. [{Cp(2)ErNHEt}(2)] reacts with an excess of PhEtCCO to give [(Cp(2)Er{PhEtCHCON(Et)COCEtPh})(2)] (7), revealing another unique pattern of double-insertion of ketenes into the metal-ligand bond without bond formation between two ketene molecules. All complexes were characterized by elemental analysis and by their spectroscopic properties. The structures of complexes 1 b, 2 a, 2 b, 5 a, 5 b, 6, and 7 were also determined through X-ray single-crystal diffraction analysis.
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Affiliation(s)
- Ruiting Liu
- Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, P.R. China
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71
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Affiliation(s)
- Edward J. Stoebenau
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637
| | - Richard F. Jordan
- Department of Chemistry, The University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637
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72
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Liu Y, Nishiura M, Wang Y, Hou Z. π-Conjugated Aromatic Enynes as a Single-Emitting Component for White Electroluminescence. J Am Chem Soc 2006; 128:5592-3. [PMID: 16637599 DOI: 10.1021/ja058188f] [Citation(s) in RCA: 340] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By use of the organolanthanide catalysts Me2Si(C5Me4)(NAr)Lu(CH2SiMe3)(THF) and (C5Me5)2LaCH(SiMe3)2, carbazole-substituted phenyl enynes (Z)-CPEY and (E)-CPEY were synthesized, respectively, with excellent regio- and stereoselectivity through the catalytic dimerization of the corresponding terminal alkyne. These new pi-conjugated compounds, in particular, the (E)-enyne isomer (E)-CPEY, act as an excellent single-emitting component for white organic light-emitting devices (WOLEDs), as a result of combination of the blue emission from an isolated molecule with the longer-wavelength emissions (green and orange-red) from excimers. The (E)-CPEY-based double-layer device emitted almost pure white light with CIE coordinates of (0.32, 0.33), maximum brightness of 1395 cd m-2, and maximum current efficiency of 2.07 cd A-1. This is perhaps the purest white emission ever reported for a single-emitting-component WOLED. The quality of the white emission remained almost unchanged under varying driving voltages, demonstrating an advantageous potential of single-emitting-component WOLEDs.
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Affiliation(s)
- Yu Liu
- Organometallic Chemistry Laboratory, RIKEN (The Institute of Physical and Chemical Research), Hirosawa 2-1, Wako, Saitama 351-0198, Japan
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73
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Zhu Z, Wang C, Xiang X, Pi C, Zhou X. DyI2 initiated mild and highly selective silyl radical-catalyzed cyclotrimerization of terminal alkynes and polymerization of MMA. Chem Commun (Camb) 2006:2066-8. [PMID: 16767277 DOI: 10.1039/b602883g] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An efficient method for the formation of SiCl3 radicals by the reaction of abundant and cheaper chlorosilanes with DyI2 has been established, not only demonstrating new distinctive reactivities of solvated DyI2 but also suggesting that the presence of lanthanide ions can improve the selectivity of some silyl radical-catalyzed reactions.
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Affiliation(s)
- Zhenyu Zhu
- Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, People's Republic of China
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74
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Bambirra S, Tsurugi H, van Leusen D, Hessen B. Neutral versus cationic Group 3 metal alkyl catalysts: performance in intramolecular hydroamination/cyclisation. Dalton Trans 2006:1157-61. [PMID: 16482351 DOI: 10.1039/b512135c] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The relative catalytic activity of neutral dialkyl versus cationic monoalkyl Group 3 metal catalysts in the intramolecular hydroamination/cyclisation of the 2,2-dimethyl-4-pentenylamine reference substrate was investigated. This was found to depend strongly on the nature of the monoanionic ancillary ligand. With a bidentate amidinate ligand, the neutral catalysts were quite effective, but their cationic derivatives showed a much lower activity. The reaction kinetics suggest that this reflects an intrinsically higher activation barrier for the insertion of the olefinic moiety into the metal-amide bond for the cationic catalysts. In contrast, the neutral catalysts with tetradentate triamine-amide ligands showed a much lower activity than their cationic derivatives. It appears that this higher activity of the cationic triamine-amide catalysts reflects the beneficial effect of the additional available coordination space relative to the neutral species. The cationic triamine-amide yttrium catalysts are more active than the cationic amidinate catalysts of the same metal, possibly reflecting a stronger Y-amide bond in the latter, which is the more electron-deficient system.
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Affiliation(s)
- Sergio Bambirra
- Centre for Catalytic Olefin Polymerisation, Stratingh Institute for Chemistry and Chemical Engineering, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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75
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Zhang WX, Nishiura M, Hou Z. Catalytic Addition of Terminal Alkynes to Carbodiimides by Half-Sandwich Rare Earth Metal Complexes. J Am Chem Soc 2005; 127:16788-9. [PMID: 16316216 DOI: 10.1021/ja0560027] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The catalytic addition of terminal alkynes to carbodiimides has been achieved for the first time by use of half-sandwich rare earth metal complexes, such as {Me2Si(C5Me4)(NPh)}Y(CH2SiMe3)(THF)2, which offers a straightforward, atom-economic route to the N,N'-disubstituted propiolamidines which contain a conjugated C-C triple bond, a new family of amidines which were difficult to prepare by other means. A rare earth metal amidinate species was confirmed to be a true catalytic species in this process, thus demonstrating for the first time that an amidinate unit, though being often used as an ancillary ligand for various organometallic complexes, can itself participate in a catalytic reaction under appropriate conditions.
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Affiliation(s)
- Wen-Xiong Zhang
- Organometallic Chemistry Laboratory, RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama, Japan
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76
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Katayama H, Yari H, Tanaka M, Ozawa F. (Z)-Selective cross-dimerization of arylacetylenes with silylacetylenes catalyzed by vinylideneruthenium complexes. Chem Commun (Camb) 2005:4336-8. [PMID: 16113740 DOI: 10.1039/b504436g] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The vinylideneruthenium(II) complexes bearing bulky and basic tertiary phosphine ligands, RuCl2(=C=CHPh)L2 (L = PPri3, PCy3), serve as good catalyst precursors for (Z)-selective cross-dimerization between arylacetylenes and silylacetylenes in the presence of N-methylpyrrolidine.
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Affiliation(s)
- Hiroyuki Katayama
- International Research Center for Elements Science (IRCELS), Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan.
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77
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Hirabayashi T, Sakaguchi S, Ishii Y. Iridium Complex-Catalyzed Cross-Coupling Reaction of Terminal Alkynes with Internal Alkynesvia CH Activation of Terminal Alkynes. Adv Synth Catal 2005. [DOI: 10.1002/adsc.200404359] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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