- Efficient rhodium catalysts for the hydrogenolysis of thiophenic molecules in homogeneous phase
-
In the presence of strong bases, the C - S insertion complexes (triphos)Rh[η3-S(C6H4)CH=CH2] and (triphos)Rh(η3-SCH=CHCH=CH2) as well as the π-alkyne complex [(triphos)Rh(η2-MeO
- Bianchini, Claudio,Casares, Juan A.,Meli, Andrea,Sernau, Volker,Vizza, Francesco,Sanchez-Delgado, Roberto A.
-
p. 3099 - 3114
(2008/10/09)
-
- Tripodal polyphosphine ligands in homogeneous catalysis. 1. Hydrogenation and hydroformylation of alkynes and alkenes assisted by organorhodium complexes with MeC(CH2PPh2)3
-
This paper describes the synthesis and the chemical-physical properties of a number of new mononuclear organorhodium complexes of triphos. A detailed study on the hydrogenation reactions of various alkenes and alkynes and on the hydroformylation reactions of alkenes has been carried out. Also, the study compares and contrasts the catalytic activity of complexes containing participative ligands with that of (i) related mononuclear species containing non-participative ligands, and (ii) related dirhodium complexes.
- Bianchini,Meli,Peruzzini,Vizza,Frediani,Ramirez
-
p. 226 - 240
(2008/10/08)
-
- η3-MeC(CH2PPh2)3/rhodium complexes utilize phosphine arm dissociation mechanisms at 25°C
-
Reaction of RhMe3(triphos) (triphos = MeC(CH2PPh2)3) with CO generates acetone and RhMe(CO)(triphos), which reacts with further CO to give Rh[C(O)Me](CO)(triphos). The structure of RhMe(CO)(triphos) shows one strained P-Rh-P bond angle between equatorial ligands (90.80 (5)°) in a trigonal bipyramid, together with intramolecular steric effects that cause a small equatorial CO-Rh-axial(CH3) C/C angle of 79.09 (25)°. The acetyl and methyl complexes react with H2 at 25°C to produce acetaldehyde and methane, respectively, together with RhH(CO)(triphos). Reaction of CO with RhH3(triphos) is even faster than with RhMe3(triphos) to give H2 and RhH(CO)(triphos), together with a CO hydrogenation product. These results show that these clean stoichiometric conversions, as well as a variety of isotopic exchange reactions of the Rh(I) and Rh(III) compounds with D2 and 13CO, occur by preequilibrium dissociation of one arm of the triphos ligand at 25°C. One such species, Rh[C(O)Me](CO)2(η2-triphos), is directly detectable and reveals the mechanism of exchange of Rh[C(O)Me](13CO)(triphos) with 12CO. The coordination of CO to Rh(H)3(η2-triphos) is proposed to generate a dihydrogen complex, thus accounting for the CO-induced elimination of H2. As suggested by these individual reactions, RhH(CO)(triphos) is a catalyst for olefin hydroformylation. The high n:iso selectivity mimics that of RhH(CO)(PPh3)3 in the presence of a large amount of added PPh3, a beneficial consequence of the chelate effect.
- Thaler, Eric G.,Folting, Kirsten,Caulton, Kenneth G.
-
p. 2664 - 2672
(2007/10/02)
-
- Gold-Rhodium and Gold-Iridium Hydride Clusters
-
The hydrides MH3(tripod) (M=Rh and Ir; tripod=triphos and triars) react with + cations to give heterometallic species of the types +, type A, 2+>, type B, and (tripod)MH2(Au(L
- Albinati, Alberto,Demartin, Francesco,Janser, Philipp,Rhodes, Larry F.,Venanzi, Luigi M.
-
p. 2115 - 2125
(2007/10/02)
-
- Rhodium Complexes with the Tripodal Triphosphine MeC(CH2PPh2)3 as Highly Reactive Systems for Hydrogenation and Hydroformylation of Alkenes
-
The (triphos)Rh fragment is able to form strong bonds with several reactive species (hydride, alkyl, carbon monoxide, alkenes), some reactions of which are highly specific; preliminary results on the hydrogenation and hydroformylation of hex-1-ene using (triphos)RhH(C2H4) as catalyst precursor are discussed.
- Bianchini, Claudio,Meli, Andrea,Peruzzini, Maurizio,Vizza, Francesco,Fujiwara, Yuzo,et al.
-
p. 299 - 301
(2007/10/02)
-
- A Family of Hydride Complexes of Rhodium. Crystal Structure of the Paramagnetic Rhodium(III)-Rhodium(II) Complex (BPh4)2*DMF
-
A family of rhodium hydrides including mono- and bi-nuclear, mono- and poly-hydride, diamagnetic and paramagnetic members has been prepared; the structure of the paramagnetic rhodium hydride (BPh4)2*DMF triphos = MeC(CH2Ph2)
- Bianchini, Claudio,Mealli, Carlo,Meli, Andrea,Sabat, Michal
-
p. 777 - 779
(2007/10/02)
-
- SOME RHODIUM(I) AND RHODIUM(III) COMPLEXES WITH THE TRIPOD-LIKE LIGANDS RC(CH2PPh2)3 (R=Me: triphos; R=Et: triphos-I) AND THE X-RAY CRYSTAL STRUCTURE OF
-
The syntheses of (8, triphos=CH3C(CH2PPh2)3) and the related compound (triphos-I=EtC(CH2PPh2)3) are described, and the X-ray crystal structure of the latter is reported.The crystals are monoclinic space group P21/a, a 15.985(6), b 19.683(7), c 11.900(4) Angstroem, β 103,73(6) degree, Z=4.The structure was solved by the heavy atom method and refined by full-matrix leastsquares to the conventional R factor value of 0.057 for 2649 observed reflections.The metal atom is octahedrally coordinated by three phophorus atoms and by three hydrogen atoms, each trans to one phosphorus.Complex 8 has been shown to react with CO to give (2).Compound 2 reacts with CH2=CHCO2Me to give only the branched insertion product .The complex has been re-investigated and was obtained in a single isomeric form which has been assigned a five-coordinate structure.The five-coordinate compounds (X=Br and I) are also described.
- Ott, J.,Venanzi, L. M.,Ghilardi, C. A.,Midollini, S.,Orlandini, A.
-
-