29949-64-2Relevant academic research and scientific papers
Ru(II)-Catalyzed Amination of Aryl Fluorides via η6-Coordination
Kang, Qi-Kai,Li, Yuntong,Lin, Yunzhi,Shi, Hang
, p. 3706 - 3711 (2020/03/11)
We developed a Ru/hemilabile-ligand-catalyzed nucleophilic aromatic substitution (SNAr) of aryl fluorides as the limiting reagents. Significant ligand enhancement was demonstrated by the engagement of both electron-rich and neutral arenes in the SNAr amination without using excess arenes. Preliminary mechanistic studies revealed that the nucleophilic substitution proceeds on a η6-complex of the Ru catalyst and the substrate, and the hemilabile ligand facilitates dissociation of products from the metal center.
Facile, Catalytic Dehydrocoupling of Phosphines Using β-Diketiminate Iron(II) Complexes
King, Andrew K.,Buchard, Antoine,Mahon, Mary F.,Webster, Ruth L.
supporting information, p. 15960 - 15963 (2015/11/03)
Catalytic dehydrocoupling of primary and secondary phosphines has been achieved for the first time using an iron pre-catalyst. The reaction proceeds under mild reaction conditions and is successful with a range of diarylphosphines. A proton acceptor is not needed for the transformation to take place, but addition of 1-hexene does allow for turnover at 50°C. The catalytic system developed also facilitates the dehydrocoupling of phenylphosphane and dicyclohexylphosphane. A change in solvent switches off dehydrocoupling to allow hydrophosphination of alkenes.
Selective dehydrocoupling of phosphines by lithium chloride carbenoids
Molitor, Sebastian,Becker, Julia,Gessner, Viktoria H.
, p. 15517 - 15520 (2014/12/12)
The development of a simple, transition-metal-free approach for the formation of phosphorus-phosphorus bonds through dehydrocoupling of phosphines is presented. The reaction is mediated by electronically stabilized lithium chloride carbenoids and affords a variety of different diphosphines under mild reaction conditions. The developed protocol is simple and highly efficient and allows the isolation of novel functionalized diphosphines in high yields.
NMR spectroscopy and structural characterization of dithiophosphinate ligands relevant to minor actinide extraction processes
Daly, Scott R.,Klaehn, John R.,Boland, Kevin S.,Kozimor, Stosh A.,MacInnes, Molly M.,Peterman, Dean R.,Scott, Brian L.
body text, p. 2163 - 2175 (2012/03/22)
Synthetic routes to alkyl and aryl substituted dithiophosphinate salts that contain non-coordinating PPh4+ counter cations are reported. In general, these compounds can be prepared via a multi-step procedure that starts with reacting secondary phosphines, i.e. HPR2, with two equivalents of elemental S. The synthetic transformation proceeds by oxidation of the phosphine followed by insertion of S into the H-P bond. This approach was used to synthesize a series of dithiophosphinic acids that were fully characterized, namely HS2P(p-CF3C6H 4)2, HS2P(m-CF3C6H 4)2, HS2P(o-MeC6H4) 2 and HS2P(o-MeOC6H4)2. Although the insertion step was found to be much slower than the oxidation reaction, the formation of (NH4)S2PR2 from HPSR2 occurred rapidly upon addition of NH4OH. Subsequent cation exchange reactions proceeded readily with PPh4Cl in water, under air and at ambient conditions to provide analytically pure samples of [PPh4][S2PR2] (R = p-CF3C 6H4, m-CF3C6H4, o-CF 3C6H4, o-MeC6H4, o-MeOC6H4, Ph, and Me, 1b-7b, respectively), which were characterized by elemental analysis, multinuclear NMR, and IR spectroscopy. In addition, S2PPh2- and dithiophosphinates with ortho-substituted aryl groups (3b-6b) were characterized by X-ray crystallography. As opposed to the acids, which have short PS double bonds and long P-SH single bonds, the metric parameters for the S atoms in S 2PR2- are equivalent. In addition, the presence of large non-coordinating PPh4+ cations guard against intermolecular P-S...X interactions and ensure that the P-S bond is isolated. These S2PR2- anions, which can be prepared in large quantities and isolated in crystalline form, are attractive for spectroscopic and theoretical studies because the P-S interaction can be probed independently in the absence of intermolecular interactions.
Synthesis of new serine-based phosphinooxazoline ligands and iridium complexes for asymmetric hydrogenations
Franzke, Axel,Voss, Felix,Pfaltz, Andreas
supporting information; experimental part, p. 4358 - 4363 (2011/08/03)
A series of serine-based phosphinooxazoline ligands was synthesized and the corresponding iridum complexes were successfully applied in the asymmetric hydrogenation of various unfunctionalized olefines and acetophenone-N-phenyl- imine. The results show that these new derivatives are useful substitutes for the standard tert-leucine-derived PHOX ligands.
Stereoelectronic factors in iron catalysis: Synthesis and characterization of aryl-substituted iron(II) carbonyl P-N-N-P complexes and their use in the asymmetric transfer hydrogenation of ketones
Sues, Peter E.,Lough, Alan J.,Morris, Robert H.
scheme or table, p. 4418 - 4431 (2011/10/10)
A series of five (S,S)-trans-[Fe(CO)(Br)(PR2-CH 2CH=NCH(Ph)CH(Ph)N=CHCH2-PR2)][X] compounds (1a-c, X = BPh4; 1d,e, X = BF4) were synthesized and tested for the asymmetric transfer hydrogena
Convenient methods for the synthesis of a library of hemilabile phosphines
Jimenez, M. Victoria,Perez-Torrente, Jesus J.,Bartolome, M. Isabel,Oro, Luis A.
body text, p. 1916 - 1922 (2009/12/28)
A series of novel functionalized phosphines of hemilabile character, R 2P(CH2)nZ, have been prepared from diarylphosphines using several synthetic methodologies. The synthetic methods include the alkylation of lithium diar
A superior method for the reduction of secondary phosphine oxides
Busacca, Carl A.,Lorenz, Jon C.,Grinberg, Nelu,Haddad, Nizar,Hrapchak, Matt,Latli, Bachir,Lee, Heewon,Sabila, Paul,Saha, Anjan,Sarvestani, Max,Shen, Sherry,Varsolona, Richard,Wei, Xudong,Senanayake, Chris H.
, p. 4277 - 4280 (2007/10/03)
(Chemical Equation Presented) Diisobutylaluminum hydride (DIBAL-H) and triisobutylaluminum have been found to be outstanding reductants for secondary phosphine oxides (SPOs). All classes of SPOs can be readily reduced, including diaryl, arylalkyl, and dialkyl members. Many SPOs can now be reduced at cryogenic temperatures, and conditions for preservation of reducible functional groups have been found. Even the most electron-rich and sterically hindered phosphine oxides can be reduced in a few hours at 50-70°C. This new reduction has distinct advantages over existing technologies.
Electron withdrawing substituents on equatorial and apical phosphines have opposite effects on the regioselectivity of rhodium catalyzed hydroformylation
Casey, Charles P.,Lin Paulsen, Evelyn,Beuttenmueller, Eckart W.,Proft, Bernd R.,Petrovich, Lori M.,Matter, Brock A.,Powell, Douglas R.
, p. 11817 - 11825 (2007/10/03)
The electronic effects of electron withdrawing aryl substituents on equatorial and apical diphosphines were investigated. Chelating diphosphines designed to coordinate in diequatorial or in apical-equatorial positions were synthesized, and their effects on the regioselectivity of rhodium catalyzed 1-hexene hydroformylation were observed, Only diequatorial coordination was observed for 2,2'-bis[(diphenylphosphino)methyl]-1,1'-biphenyl (BISBI) complexes (BISBI)Ir(CO)2H (8) and [BISBI-(3,5-CF3)]Ir(CO)2H (10), and only apical-equatorial coordination was seen for 1,2-bis(diphenylphosphino)ethane (DIPHOS) complexes (DIPHOS)Ir(CO)2H (14) and [DIPHOS-(3,5-CF3)]Ir(CO)2H (15). For the trans-1,2-bis[(diphenylphosphino)methyl]cyclopropane (T-BDCP) complexes, a mixture of diequatorial and apical-equatorial complexes was seen. For (T-BDCP)Ir(CO)2H (12), 12-ae was favored over 12-ee by 63:37, but for [T-BDCP-(3,5-CF3)]Ir(CO)2H (13) the conformational preference was reversed and a 10:90 ratio of 13-ae:13-ee was seen. The electron withdrawing groups in the equatorial positions of BISBI-(3,5-CF3) (1) and T-BDCP-(3,5-CF3) (2) led to an increase in n-aldehyde regioselectivity in rhodium catalyzed hydroformylation. However, electron withdrawing aryl substituents in the apical positions of DIPHOS-(3,5-CF3) (3) led to a decrease in n-aldehyde regioselectivity in rhodium catalyzed hydroformylation.
