17966-79-9Relevant academic research and scientific papers
π effects involving Rh-PZ3 compounds. The quantitative analysis of ligand effects (QALE)
Wilson, Matthew R.,Prock, Alfred,Giering, Warren P.,Fernandez, Anthony L.,Haar, Christopher M.,Nolan, Steven P.,Foxman, Bruce M.
, p. 2758 - 2763 (2002)
Through the quantitative analysis of ligand effects (QALE), we have probed π effects associated with Rh-P bond lengths, vco, and -ΔHrx for Rh(CO)(Cl)(PX3)2 and νCO and - ΔHrx for Rh(acac)(CO)(PZ3). It was found that π effects are complex and depend strongly on the nature of ancillary or other participatory groups. The results of the QALE analysis of - ΔHrx point out the importance of synergistic interactions between PZ3 and other ancillary ligands in accord with theoretical computations. Literature data for Rh(CO)(Cl)(PZ3)2 have been supplemented with new values of ΔHrx for PMe3 (-75.6 ± 0.3 kcal/mol), P(i-Pr)3 (-68.7 ± 0.3 kcal/mol), and PCy3 (-66.4 ± 0.4 kcal/mol) as well as crystal structures for Rh(CO)(Cl)(P(i-Pr3))2 (Rh-P = 2.3488(3) A?) and Rh(CO)(Cl)(PCy3)2 (Rh-P = 2.3508(3)).
Chiral monodentate trialkylphosphines based on the phospholane architecture
Donets, Pavel A.,Saget, Tanguy,Cramer, Nicolai
, p. 8040 - 8046 (2013/02/22)
The development of efficient chiral monodentate phosphine ligands lags behind that of the bidentate congeners. This holds especially true for highly electron rich chiral phosphine analogues able to replace the ubiquitous tricyclohexylphosphine and tri-tert-butylphosphine in catalytic asymmetric transformations. We present a convenient and modular synthesis of a set of chiral monodentate ligands with different steric demands based on the popular phospholane scaffold. Their steric and electronic properties were determined by their corresponding nickel and palladium complexes. They represent good mimics of the popular tricyclohexylphosphine and tri-tert-butylphosphine ligands. Their potential was subsequently evaluated in palladium-catalyzed asymmetric C(sp3)-H functionalization leading to indolines.
P-N bond formation as a route to highly electron rich phosphine ligands
Clarke,Cole-Hamilton,Slawin,Woollins
, p. 2065 - 2066 (2007/10/03)
Phosphines containing two N-bound pyrrolidine groups and one alkyl or aryl group are unusually electron rich σ-donor ligands when compared to either tris(N-pyrrolidinyl)phosphine or trialkyl- and triaryl-phosphines.
Preparation and Reactivity of Iodomethyl Complexes of Rhodium(III); Crystal and Molecular Structure of Carbonylchloroiodo(iodomethyl)bis(triethylphosphine)rhodium(III)
Gash, Rosslyn C.,Cole-Hamilton, David J.,Whyman, Robin,Barnes, John C.,Simpson, Michael C.
, p. 1963 - 1970 (2007/10/02)
Diiodomethane oxidatively added to formed for R3=Me3, Et3 or Et2Ph but not for R3=EtPh2, Ph3, (C6H11)3 or (OMe)3; CH2Br2 gave a mixture of bromo- and chloromethyl complexes whilst CH2ICl gave two isomers of with I or Cl trans to CH2Cl.In polar solvents or on treatment with water or MeOH, underwent a halide-scrambling reaction to give several compounds containing CH2I or CH2Cl ligands which have been identified spectroscopically.The same scrambling occurs under high pressures of CO, although IR, NMR and model studies suggest the Rh-C(O)CH2X species are also formed by insertion of CO into the Rh-CH2X bond.Most of the acyl products are unstable to loss of ketene, but one may be stable -1>.The complex has been characterised crystallographically: triclinic, space group P, a=12.343(3), b=14.327(2), c=15.426(2) Angstroem, α=113.78(1), β=67.25(1), γ=90.20(1) deg, Z=4, R=0.0453.Each unit cell contains two pairs of molecules differing in the relative orientations of one PEt3 ligand.In both cases, Rh-C , C-I and Rh-C-I are similar to those reported for related compounds.Both molecules have mutually trans phosphines and CH2I trans to I.
Relative affinities of carbonylbis(triphenylphosphine)rhodium(I) and related cations for anionic ligands in CH2Cl2
Araghizadeh, Farshid,Branan, Daniel M.,Hoffman, Norris W.,Jones, John H.,McElroy, E. Andrew,Miller, Nathan C.,Ramage, David L.,Salazar, Anna Battaglia,Young, Sidney H.
, p. 3752 - 3755 (2008/10/08)
Infrared spectroscopy has been used to determine the relative anion affinities in CH2Cl2 of Rh(PPh3)2(CO)+ and Rh(AsPh3)2(CO)+ via measurement of equilibrium constants for the metatheses RhL2(CO)Y + PPN+Z- = RhL2(CO)Z + PPN+Y-. Observed for L = PPh3 was the anion affinity trend NCO- ? O2CMe- ～ O2CPh- ? F- ～ NCS- > Cl- > Br- > I- ? ONO2- ～ O2CCF3- ? OTf- ～ OClO3-. A smaller series for L = AsPh3 displayed a similar trend, but with positions of NCS- and Cl- reversed. For most anion pairs studied, the equilibrium lies so far to the left or right that only limits could be calculated, given the inherent experimental limitations. For L = PPh3, the equilibrium constant for replacement of the least preferred anion by the most can be inferred as >1019. Rh(PCy3)2(CO)Cl and Rh(PCy3)2(CO)Z (Z = NCS, NCSe, O2CMe; but not F, O2CPh, and NCO) interact strongly in solution and thus limit study of that series.
Synthesis and Chemistry of trans-2> (X = Anionic Ligand, L = Tertiary Phosphine)
Ohgomori, Yuji,Yoshida, Shin-ichi,Watanabe, Yoshihisa
, p. 2969 - 2974 (2007/10/02)
The novel preparation of a wide variety of trans-2> complexes (X = anionic ligand, L = tertiary phosphine) from , phosphine (L), and acid (HX) is described.A plausible formation pathway is proposed.The electron density on the phosphorous atom in trans-2> decreases and the length of the Rh-P bond increases with an increase in the electronegativity of the anionic ligand, X, in a cis position to the phosphine ligand.The rhodium complexes (X = arylcarboxylate) are reduced to afford rhodate anions such as - and - in hexamethylphosphoroamide solution under CO-H2.The rate of reduction increases with a decrease in the electron-withdrawing effect of the arylcarboxylate ligand.
SCHWEFEL(IV)-VERBINDUNGEN ALS LIGANDEN VI. KOORDINATIVE UND OXIDATIVE ADDITION AN QUADRATISCH-PLANARE IRIDIUM-SCHWEFELDIOXID-KOMPLEXE
Schenk, Wolfdieter A.,Leissner, Johanna
, p. C27 - C30 (2007/10/02)
The sulfur dioxide complexes Ir(PR3)2Cl(SO2) (R=i-Pr, cyclohexyl) react with CO to give the corresponding carbonyls Ir(PR3)2Cl(CO) via the unstable intermediates Ir(PR3)2Cl(CO)(SO2).With H2 and HCl they form the oxidative-addition products IrH2(PR3)2Cl(SO
Four- and Five-Coordinated Sulfur Monoxide Complexes of Rhodium and Iridium
Schenk, Wolfdieter A.,Leissner, Johanna,Burschka, Christian
, p. 1264 - 1273 (2007/10/02)
The complexes trans- (M = Rh, Ir; R = isopropyl, cyclohexyl) were synthesized from 2, PR3 and C2H4SO.The X-ray structure of shows the sulfur monoxide to be coordinated in a bent η1 fashion.A bonding model is proposed which explains the similarity between SO- and SO2-complexes.Peracid oxidation transforms coordinated SO to SO2.CO displaces SO via isolable 5-coordinated intermediates . - Key words: Sulfur Monoxide Complexes, Synthesis, Structure, Bonding, Peracid Oxidation, SO-Displacement
Co-ordination Chemistry of Sulphines. Part 5. ?-S ang η-SCS Co-ordination of Sulphines to Rhodium(1). Fluxional Behaviour of ICl-(PR3)(XYCSO)> (R=alkyl; X,Y=aryl, S-aryl, S-alkyl, or Cl) Complexes and Influence of Suphine Geometry on the Formation of ICl(PR3)2(XYCSO)>.
Gosselink, Johan W.,Brouwers, Anja M. F.,Koten, Gerard van,Vrieze, Kees
, p. 397 - 406 (2007/10/02)
Sulphines react with ICl(cyclo-C8H14)2>2> and PR3 (R=C6H11 or iPr) to afford complexes of the type ICl(PR3)n(sulphine)> (n=1 or 2), in which the number of phosphines depends on the nature of the sulphine side bonds.If no reactive (C-S, C-Cl) side bonds are present, the sulphine co-ordinates via ?-S to RhI with two phosphines in trans positions.If one of two C-S side bonds are present the sulphine co-ordinates η3-SCS to a phosphines in trans positions.None of these complexes undergoes a C-S oxidative-addition reaction.For the η3-SCS to co-ordinated complexes ICl(PR3)> and ICl(PR3)> (R=C6H11 or iPr, R'=C6H4-Me-p or Ph) a fluxional process is found (31P and 1H n.m.r.), which can be described either as an (E)-(Z) isomerization of the MeS, p-MeC6H4S, or PhS group of the co-ordinated side bonds or as an intramolecular PR3-Cl interchange.For the corresponding (Z) stereoisomers this process could not be detected.The complex ICl>,(E)-(2b), and P(C6H11)3 form an equilibrium mixture with trans-ICl2>, (E)-(4b), in which the sulphine is ?-S co-ordinated.On the other hand the corresponding (Z) stereoisomer, (Z)-(2b), is in equilibrium with P(C6H11)3 and cis-ICl2>, (Z)-(6b), a five-co-ordinate rhodium(I) complex with an η3-SCS co-ordinated sulphine.This difference between the (E) and (Z) stereoisomers can be understood in terms of the geometric arrangement of the pseudo-allylic co-ordination.
