15613-32-8Relevant articles and documents
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.
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.
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.
