39796-96-8Relevant academic research and scientific papers
Generation of metal formyl complexes using nickel and platinum hydrides as reducing agents
Miedaner, Alex,DuBois, Daniel L.,Curtis, Calvin J.,Haltiwanger, R. Curtis
, p. 299 - 303 (1993)
The five-coordinate nickel hydride complex [Ni(dmpe)2H]PF6 (1) [dmpe = 1,2-bis-(dimethylphosphino)ethane] was synthesized by protonation of Ni(dmpe)2 with NH4PF6. The platinum analog, [Pt(dmpe)2H]PF6 (2), and [Pt(depe)2H]PF6 (3) [depe = 1,2-bis(diethylphospnino)ethane] were synthesized by reduction of the corresponding Pt(II) complexes with NaBH4 on alumina. Complexes 1 and 3 can also be synthesized electrochemically. Reduction of Ni-(dmpe)22+ by two electrons in the presence of ammonium ion generates 1, and reduction of Pt(depe)22+ in methanol or wet acetonitrile produces 3. These hydrides react with a variety of cationic metal carbonyl complexes to produce known metal formyl complexes. The structure of 3 was determined by X-ray diffraction. Complex 3 crystallizes in a monoclinic unit cell with P21/c symmetry with a = 14.258 (4) ?, b = 9.648 (3) ?, c= 21.898 (5) ?, β = 91.17 (2)°, V = 3011.7 (14) ?3, Z = 4, and dcalcd = 1.662 g/cm3. Full-matrix least-squares refinement converged with residuals R = 4.52% and Rw = 5.90%.
Dichotomy of Manganese Catalysis via Organometallic or Radical Mechanism: Stereodivergent Hydrosilylation of Alkynes
Yang, Xiaoxu,Wang, Congyang
supporting information, p. 923 - 928 (2018/01/01)
Herein, we disclose the first manganese-catalyzed hydrosilylation of alkynes featuring diverse selectivities. The highly selective formation of E-products was achieved by using mononuclear MnBr(CO)5 with the arsenic ligand, AsPh3. Whereas using the dinuclear catalyst Mn2(CO)10 and LPO (dilauroyl peroxide) enabled the reversed generation of Z-products in good to excellent stereo- and regioselectivity. Such a way of controlling the reaction stereoselectivity is unprecedented. Mechanistic experiments revealed the dichotomy of manganese catalysis via organometallic and radical pathways operating in the E- and Z-selective routes, respectively.
Synthesis and thermolysis of neutral metal formyl complexes of molybdenum, tungsten, manganese, and rhenium
Gibson,Owens,Mandal,Sattich,Franco
, p. 498 - 505 (2008/10/08)
The possible intermediacy of catalyst-bound formyls in syngas transformations has prompted efforts to prepare and study the chemistry of transition-metal formyl complexes over more than a decade. We have used a mild borohydride in our reactions with metal carbonyl cations and have introduced some variations into the syntheses which allow, in almost all cases, for the pure formyl complex to be precipitated from solution as it is formed. The formyl complexes and their cationic precursors are shown. Seven of the formyls are new; improved procedures have been established for the other four. All but one of the compounds have been isolated.
CARBONYLATION AND HYDROGENATION OF cis-CH3Mn(CO)4L, SUBSTITUTIONAL REACTIVITY OF cis-HMn(CO)4L, AND BINUCLEAR ELIMINATION BETWEEN cis-CH3Mn(CO)4P(OPh)3 AND cis-HMn(CO)4P(OPh)3 (L = CO, PPh3, P(OPh)3, PBu3 AND P(OMe)3)
Ruszczyk, Ronald J.,Huang, Bih-Lian,Atwood, Jim D.
, p. 205 - 212 (2007/10/02)
Several reactions of cis-CH3Mn(CO)4L and cis-HMn(CO)4L, have been investigated.The carbonylation of cis-CH3Mn(CO)4L (L = CO, P(OPh)3, P(OMe)3, and PBu3) shows a very small ligand effect, indicating a transition state that has little unsaturation.Reaction with H2 has very similar observed rate constants and activation parameters to the carbonylation.The hydrides, cis-HMn(CO)4L (L = P(OPh)3, PPh3 and PBu3), are remarkably unreactive toward substitution, requiring temperatures of 100 deg C.A radical mechanism is most likely.Reactions of cis-HMn(CO)4P(OPh)3 with cis-CH3Mn(CO)4P(OPh)3 and cis-HMn(CO)4PBu3 with CH3C(O)Mn(CO)5 occur at temperatures where methyl migration is readily established and the hydride complexes are unreactive.Thus methyl migration, followed by coordination to a bridging hydride, is indicated for these binuclear reductive elimination reactions.
REDUCTIONS OF METAL CARBONYLS BY QUATERNARY AMMONIUM BOROHYDRIDES
Gibson, Dorothy H.,Ahmed, Fahim U.,Phillips, Kenneth R.
, p. 325 - 336 (2007/10/02)
Quaternary ammonium borohydrides, used directly or generated in phase transfer reactions, are highly effective reagents for preparing metal carbonyl anions from metal carbonyls 5-C5H5)2Mo2(CO)6> and from some metal carbonyl halides 5-C5H5Mo(CO)3Cl>.Where strongly basic anions would be fromed from a halide 5-C5H5Ru(CO)2Br>, the reactions provide efficient syntheses of the corresponding hydrides instead.The anion η5-C5H5Fe(CO)2- is not accessible bythese techniques; reaction of η5-C5H5Fe(CO)2Br yields the iron dimer (via the highly nucleophilic anion) and the dimer is unreactive toward Q+BH4-.Reductions of Re2(CO)10 conducted in CH2Cl2 provide Re2(CO)9Cl- in high yield.
