15613-32-8Relevant academic research and scientific papers
Substituent effect on reactions of ReH5(PMe2Ph)3 with propargyl alcohols
He, Guomei,Chen, Jiangxi,Sung, Herman Ho-Yung,Williams, Ian Duncan,Jia, Guochen
, (2021/02/09)
Reactions of the rhenium polyhydride ReH5(PMe2Ph)3 with propargyl alcohols in the presence of HCl can produce γ-hydroxycarbyne, vinylcarbyne and η2-vinyl complexes, the relative amounts of which are dependent on the substituents of the propargyl alcohols. The reaction with the bis-alkyl substituted propargyl alcohol HC[tbnd]CC(OH)Me2 produced only the vinylcarbyne complex ReCl2(≡CCH=CMe2)(PMe2Ph)3. The reaction with the bis-alkynyl substituted propargyl alcohol HC[tbnd]CC(OH)(C[tbnd]CSiMe3)2 produced only the η2-vinyl complex ReCl2{ η2-CH2=CC(OH)(C[tbnd]CSiMe3)2}(PMe2Ph)3. The reactions with the bis-(o-functionalized aryl) substituted propargyl alcohols HC[tbnd]CC(OH)Ar2 (Ar = o-C6H4Br, o,o'-C6H3Cl2) produced only the γ-hydroxycarbyne complexes Re{≡CCH2C(OH)Ar2}Cl2(PMe2Ph)3. The reactions with the monoaryl substituted propargyl alcohol HC[tbnd]CC(OH)Ph(C[tbnd]CSiMe3) produced a mixture of the vinylcarbyne Re{≡CCH=CPh(C[tbnd]CSiMe3)}Cl2(PMe2Ph)3, the γ-hydroxycarbyne Re{≡CCH2C(OH)Ph(C[tbnd]CSiMe3)}Cl2(PMe2Ph)3 and the η 2-vinyl complex Re{η2-CH2=CC(OH)Ph(C[tbnd]CSiMe3)}Cl2(PMe2Ph)3. The selectivity for the products can be related to the steric and electronic effect of the substituents of propargyl alcohols. In general, formation of η2-vinyl complexes is favored over carbyne complexes when the substituents are sterically less demanding. Formation of γ-hydroxycarbyne complexes is favored over vinylcarbyne complexes when the substituents are electron withdrawing.
Hydrogen shift reactions of rhenium hydrido carbyne complexes
Chen, Jiangxi,Shi, Chuan,Sung, Herman Ho-Yung,Williams, Ian Duncan,Lin, Zhenyang,Jia, Guochen
, p. 1817 - 1824 (2012/04/23)
Rhenium hydrido carbyne complexes Re(≡CCH=C(CMe3) C≡CR)HCl(PMe2Ph)3 (R = H, n-pentyl) undergo 1,2-hydrogen shift reactions from the metal to the carbyne carbon atom to give complexes Re(HCCHC(CMe3)CCR)HCl(PMe2Ph)3, which have two isomeric forms, namely, a metallabicyclo[3.1.0]hexatriene complex, in which the chloride is cis to the metal-bonded CH, and an alkyne-carbene complex, in which the chloride is trans to the metal-bonded CH. In contrast, a similar transformation does not occur for the analogous complex Re(≡CCH=C(CMe 3)C≡CSiMe3)HCl(PMe2Ph)3, which has a SiMe3 group on the C≡C moiety. A computational study suggests that the difference in the reactivity of the hydrido carbyne complexes is related to steric effects in the corresponding hydride-shift products. Formation of Re(HCCHC(CMe3)CCSiMe3)HCl(PMe 2Ph)3 is not favored, mainly due to the steric interactions of the SiMe3 group with CMe3 and one of the phosphine ligands in the resulting metallabicyclo[3.1.0]hexatriene complex, and of the SiMe3 group with the chloride ligand in the resulting alkyne-carbene complex.
Rhenium carbyne and η2-vinyl complexes from one-pot reactions of ReH5(PMe2Ph)3 with terminal alkynes
Chen, Jiangxi,He, Guomei,Sung, Herman Ho-Yung,Williams, Ian Duncan,Lin, Zhenyang,Jia, Guochen
, p. 2693 - 2701 (2010/08/06)
Treatment of the rhenium polyhydride complex ReH5(PMe 2Ph)3 with HC≡CR (R = Ph, SiMe3, (CH 2)4Me) in the presence of 2.2 equiv of HCl produces a mixture of the carbyne complexes Re(≡CCH2R)Cl 2(PMe2Ph)3 and the η2-vinyl complexes Re(η2-CH2CR)Cl2(PMe 2Ph)3. When HC≡CC(OH)Ph2 was used, the reaction gave the carbyne complexes Re(≡CCH=CPh2)Cl 2(PMe2Ph)3 and Re(≡CCH 2C(OH)Ph2)Cl2(PMe2Ph)3 along with the η2-vinyl complex Re(η2-CH 2CC(OH)Ph2)Cl2(PMe2Ph)3.
Properties of the polyhydride anions [WH5(PMe 2Ph)3]- and [ReH4(PMePh 2)3]- and periodic trends in the acidity of polyhydride complexes
Hinman, Justin G.,Lough, Alan J.,Morris, Robert H.
, p. 4392 - 4401 (2008/10/09)
The new anionic complexes [K(18-crown-6)][WH5(PMe 2Ph)3], [K(1,10-diaza-18-crown-6)][WH5(PMe 2Ph)3], [K(2,2,2-crypt)][ReH4(PMePh 2)3], and [K(1,10-diaza-18-crown-6)][ReH 4(PMePh2)3] were prepared by reaction of KH/crown or KH/crypt with the appropriate neutral polyhydride WH 6(PMe2Ph)3 or ReH5(PMePh 2)3. The rate of deprotonation of the rhenium hydride in THF is much greater for the reaction involving crypt compared with that of crown. The structure of [ReH4(PMePh2)3] - is distorted pentagonal bipyramidal as determined by an X-ray diffraction study of the crypt salt. No hydridic-protonic M-H...HN bonding is detected between the hydrides of the anionic hydrides and the amino hydrogens of the cations [K(1,10-diaza-18-crown-6)]+ suggesting that stronger M-H...K interactions are present. Acid dissociation constants Ka of polyhydride complexes in THF, approximately corrected for ion pairing, are determined by NMR in order to better understand the periodic trends of metal hydrides. The pKαTHF of (WH6(PMe 2Ph)3/[WH5(PMe2Ph)3] -) is 42 ± 4 according to the equilibrium set up by reacting WH6(PMe2Ph)3 with [K(2,2,2-crypt)][ReH 6(PCy3)2]. The pKα THF for ReH5(PMePh2)3 can be estimated as greater than the pKαTHF of 38 for HNPh2 and less than the pKαTHF of 41 for ReH7(PCy3)2. Reaction of the phosphazene base P4-tBu with ReH7-(PCy3)2 gave an equilibrium with [HP4-tBu]+[ReH 6(PCy3)2]_ whereas reaction with WH6(PMe2Ph)3 gave an equilibrium with [HP 4-tBu]+[WH5(PMe2Ph) 3]-. From these and a related equilibrium, the pK αTHF of [HP4-tBu]+ is found to be 40 ± 4. In general, neutral complexes MH x(PR3)n (M = W, Re, Ru, Os, Ir; n = 3, 2) studied to date have pKαTHF values from 30 to 44 on going from phenyl-substituted to alkyl-substituted phosphine ligands whereas MHx(PR3)n+ (M = Re, Fe, Ru, Os, Co, Rh, Ni, Pd, Pt; n = 4, 3), including diphosphine ligands ((PR3) 2 = PR2-PR2), have values from 12 to 23. From the equilibrium established from the reaction of [HP2- tBu][BPh4] and [K(2,2,2-crypt)]-[OP(OEt)2NPh], [HP2-tBu]+ was calculated to have a pK αTHF of 30 ± 4. The equilibrium constant for the similar deprotonation reaction with [K(18-crown-6)][{ReH 2(PMePh2)2}2(μ-H)3] confirmed this value.
Regioselective electrophilic substitution and addition reactions at an N-coordinated pyrrolyl ligand in (PMe2Ph)3Cl2Re(NC4H4)
DuBois, M. Rakowski,Vasquez, Lisa D.,Peslherbe,Noll
, p. 2230 - 2240 (2008/10/08)
The reaction of excess pyrrolyllithium with mer-(PMe2Ph)3ReCl3 leads to the formation of the air-stable product mer-(PMe2Ph)3Cl2Re(NC4H4) (1), which has been characterized by spectroscopic techniques and by an X-ray diffraction study. Complex 1 reacts with electrophiles to form new Re(III) complexes with regioselectively substituted pyrrolyl ligands. For example, reaction with 1 equiv of N-chlorosuccinimide forms the complex with a 3-chloropyrrolyl ligand, while reaction with excess reagent produces the 3,4-dichloropyrrolyl and 2,3,4-trichloropyrrolyl complexes. The regiochemistry of the reactions has been established from the 1H NMR data, and the structure of the dibrominated product (PMe2-Ph)3Cl2Re(3,4-NC4H 2Br2) (5) has been confirmed by X-ray diffraction. Reaction of 1 with methyl triflate produces after workup (PMe2Ph)3Cl2Re(3-NC4H3Me) (6), and further reaction of 6 with methyl triflate yields (PMe2Ph)3Cl2Re(3,4-NC4H 2(Me)2) (7). In contrast, triflic acid protonates the pyrrolyl ligand of 1 at the α-carbon to form [(PMe2Ph)3Cl2Re(NC4H 5)]OTf (8), which has been isolated and identified by an X-ray diffraction study. The Michael addition of dimethyl acetylenedicarboxylate to the β-carbon of the pyrrolyl ligand in 1 has also been characterized. Methods for the removal of the substituted pyrrolyl ligands from the rhenium center are described.
Photochemistry of trichloro(carbonyl)tris(dimethylphenylphosphine)rhenium(III) in low temperature media
Rest, Antony J.,Wilson, Mark J.,Barra, E. Cecilia,Reveco, Patricio G.
, p. C21 - C23 (2007/10/02)
Infrared and ultraviolet-visible spectroscopic evidence is presented to show that photolysis of ReCl3(CO)(PMe2Ph)3 in poly(vinyl chloride) films and caesium iodide discs at ca. 12 K affords, irreversibly, free CO and presumably the fac-ReCl3(PMe2Ph)3 isom
