1641-40-3Relevant articles and documents
Ring size effects in cyclic fluorophosphites: Ligands that span the bonding space between phosphites and PF3
Miles-Hobbs, Alexandra M.,Hunt, Eliza,Pringle, Paul. G.,Sparkes, Hazel A.
, p. 9712 - 9724 (2019)
The 5- to 8-membered cyclic fluorophosphites L5-8 have been prepared from the corresponding chlorophosphites which are derived from dihydroxyarenes or bis(trimethylsiloxy)arenes. Ligand L5 is very sensitive to hydrolysis but L6-8 are much more kinetically robust. The coordination chemistry of L5-8 has been explored with Mo(0), Pt(0) and Rh(i) and it is shown that the π-acceptor properties of L5-8 increase with decreasing ring size. The IR spectra and X-ray crystal structures of the [Mo(CO)4L2] complexes show that L5-8 lie between PF3 and P(OAr)3 in terms of their σ/π-bonding properties. The [PtL4] complexes are readily prepared from [Pt(nbe)3] and 4 equiv. of L5-8 whereas equilibrium mixtures of PtLx(nbe)y species form when 2 equiv. of L5-8 are added to [Pt(nbe)3]. The CO substitution reactions of [Rh2Cl2(CO)4] with L5-8 to give [Rh2Cl2L4] are evidence of the PF3-like ligand properties of L5-8. The trends in the properties of L5-8 are analysed in terms of their proximity to PF3 or P(OPh)3.
Thermoregulated phase-transfer ligands and catalysis. Part VI. Two-phase hydroformylation of styrene catalyzed by the thermoregulated phase-transfer catalyst OPGPP/Rh
Chen, Ruifang,Liu, Xiaozhong,Jin, Zilin
, p. 201 - 204 (1998)
A novel nonionic water-soluble octylpolyglycol-phenylene-phosphite (OPGPP) was synthesized and the two-phase hydroformylation of styrene catalyzed by an OPGPP/Rh catalyst was investigated fully. The catalyst displayed excellent catalytic activity; high styrene conversion and high aldehyde yield (99.6 and 99.3%, respectively) were obtained at 80°C and 5.0 MPa, and the molar ratio of branched/normal aldehyde was 4.8. The experimental results revealed that there was a 'thermoregulated phase-transfer catalysis (TRPTC)' process present in the reactions.
Metathesis for catalyst design: Metacatalysis
Khumsubdee, Sakunchai,Burgess, Kevin
, p. 1326 - 1335 (2014/02/14)
Prior studies have shown an effective way to produce diverse ligand sets for catalyst discovery is by using mixtures of monodentate forms to generate catalysts in situ. Research described here was performed to illustrate that alkene-functionalized monodentate ligands could be used in this way and in another that increases the diversity of the ligand library in an interesting way. Specifically, we hypothesized that as well as being used as monomers, these alkenes could be cross metathesized in situ immediately before the catalysis step. This combination of metathesis to form ligands in situ, then catalysis is referred to here as metacatalysis. In the event, a library of quinidine and quinine alkaloid-derived phosphites were tested as mixtures of monomers and dimers formed via metathesis in situ. The data obtained illustrated that metacatalysis can be used to identify ligands that positively and negatively modulate enantioselectivities in iridium-mediated hydrogenations of α,β-unsaturated carboxylic acid derivatives, relative to the mixtures of the monomeric forms used.
IR, proton, and carbon-13 NMR spectral characterization of some chiral and achiral aminophosphines and their selenides
Gopalakrishnan, Janarthanan,Rao, M. N. Sudheendra
scheme or table, p. 754 - 764 (2010/07/05)
Though aminophosphines have been known for a century, and a large variety of such compounds has been synthesized for different aspects of their chemistry, until now, no examples are available on phosphines containing three different amino substituents. In this study, the first examples of such chiral tris(amino)phosphines and o-phenylenedioxo(amino)phosphines were successfully synthesized using condensation reactions, and they were converted to their respective selenides using a simple oxidative addition reaction. The compounds are characterized by IR, 1H, and 13C NMR spectral techniques, and the spectral aspects are presented. The spectral studies (i) indicated that they are indeed powerful tools for structural elucidation of compounds; (ii) showed the effect of heavier selenium atom on the P-N bond rotation process; and (iii) further supported the fact that dipolar structure predominates over the -bond structure for the aminophosphine selenides. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
