In an article, published in an article, once mentioned the application of 1608-26-0, Name is Tris(dimethylamino)phosphine
,molecular formula is P[N(CH3)2]3, is a conventional compound. this article was the specific content is as follows.category: chiral-phosphine-ligands
Nucleophilic addition of tris(dialkylamino) phosphines, P(NR2)3 (R = Me or Et, nPr), to [Fe2(CO)6(mu-PPh2){mu-eta 1:eta2-(H)Calpha=Cbeta=C gammaH2}] (1) affords the dimetallacyclopentene derivatives [Fe2(CO)6(mu-PPh2)(mu-eta 1:eta1-HC=C{P(NR2)3}CH 2)] (R = Me, 2a; R = Et, 2b; R = nPr, 2c) or a mixture of the vinylidene- and dimetallacyclobutene-bridged complexes [Fe2(CO)6(mu-PPh2)-(mu-eta 1-C=C(CH3){P(NMe2)3})] (3a) and [Fe2(CO)6(mu-PPh2)(mu-eta 1:eta1-(CH3)C=C{P(NMe2) 3})] (4a), respectively, depending upon the reaction conditions. For instance, addition of P(NR2)3 to an ether solution of [Fe2(CO)6(mu-PPh2){mu-eta 1:eta2-(H)Calpha=Cbeta=C gammaH2}] gave the dimetallacyclopentenes 2a-c, whereas pretreatment of a solution of the allenyl starting material with HBF4 prior to the addition of P(NR2)3 gave the vinylidene- and dimetallacyclobutene-bridged products, which co-crystallized as a 67:33 mixture, as determined by single-crystal X-ray crystallography and 1H NMR spectroscopy. We have subsequently shown that the sigma-eta-allenyl complex [Fe2(CO)6(mu-PPh2){mu-eta 1:eta2-(H)Calpha=Cbeta=C gammaH2}] undergoes a clean and quantitative acid-promoted rearrangement to the sigma-eta-acetylide-bridged isomer [Fe2(CO)6(mu-PPh2){mu-eta1: eta2-C?CH3}] (5). 1H NMR and deuterium labeling studies suggest that this isomerization occurs via initial protonation at Cgamma to afford a kinetic intermediate which rapidly rearranges to its thermodynamically more stable propyne-bridged counterpart followed by deprotonation. Clearly, the vinylidene and dimetallacyclobutene products isolated from the reaction between 1 and tris(dialkylamino) phosphine in the presence of acid arise from nucleophilic addition to the alpha- and beta-carbon atoms of the acetylide bridge in [Fe2(CO)6(mu-PPh2){mu-eta 1:eta2-C?CCH3}], and not from nucleophilic addition followed by hydrogen migration. In refluxing toluene, the dimetallacyclopentenes [Fe2(CO)6(mu-PPh2)(mu-eta 1:eta1-HC=C{P(NR2)3}CH 2)J slowly decarbonylate to give [Fe2(CO)5(mu-PPh2)(mu-eta 1:eta3-C(H)C{P(NR2)3}CH 2)] (R = Me, 6a; R = Et, 6b; R = nPr, 6c) bridged by a sigma-eta3-coordinated vinyl carbene. In the case of R = Et and nPr a competing isomerization also affords the highly unusual zwitterionic alpha-phosphoniumalkoxide-functionalized sigma-sigma-alkenyl complex [Fe2(CO)5(mu-PPh2){mu-eta 1:eta2-{P(NR2)3}C(O)CHC= CH2}] (R = Et, 7b; R = nPr, 7c), via a P(NR2)3-carbonyl-allenyl coupling sequence. In contrast, isomerization of dimetallacyclopentene [Fe2(CO)6(mu-PPh2)(mu-eta 1:eta1-HC=C{PPh3}-CH2)] (8) to its sigma-eta-alkeny] counterpart [Fe2(CO)5(mu-PPh2){mu-eta 1:eta2-PPh3C(O)CHC=CH2}] (9) is essentially complete within 1 h at room temperature with no evidence for the formation of the corresponding vinyl carbene. Thermolysis of a toluene solution of 8 in the presence of excess P(NEt2)3 results in exclusive formation of 7b, whereas at room temperature phosphine substitution affords 2b, via PPh3-P(NEt2)3 exchange. The isomerization of 8 to 9 and 2b,c to 7b,c appears to involve a dissociative equilibrium between the kinetic regioisomeric intermediate dimetallacyclopentene and 1, nucleophilic attack of phosphine at a carbonyl ligand of 1 to give a zwitterionic acylate intermediate, followed by acyl-allenyl coupling to afford the thermodynamically favored zwitterionic sigma-eta-alkenyl derivative. Qualitatively, the rate of isomerization increases as the steric bulk of the phosphine increases, in the order P(NMe2)3 < P(NEt2)3 ? P(NnPr2)3 < PPh3. The single-crystal X-ray structures of 2a, 3a, 4a, 6b, 7b, 8, and 9 are reported. Do you like my blog? If you like, you can also browse other articles about this kind. category: chiral-phosphine-ligands. Thanks for taking the time to read the blog about 1608-26-0
Reference：
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate