- Copper-catalyzed C–P cross-coupling of secondary phosphines with (hetero)aromatic bromide
-
A novel and convenient approach to the synthesis of various tertiary phosphines via a copper-catalyzed cross-coupling of (hetero)aromatic bromide with secondary phosphines has been developed. The reaction employs cheap copper as the catalyst, 2,6-bis(N-methylaminomethyl)pyridine (L4) as a perfect ligand and KOtBu as a base; all reactions are carried out under argon atmosphere. A variety of sterically hindered and/or functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields. Moreover, ten new tertiary phosphines were first reported in this process.
- Li, Chun-Jing,Lü, Jing,Zhang, Zhi-Xun,Zhou, Kun,Li, Yan,Qi, Guang-Hui
-
p. 4547 - 4562
(2018/04/20)
-
- Rapid Metal-Free Formation of Free Phosphines from Phosphine Oxides
-
A rapid method for the reduction of secondary phosphine oxides under mild conditions has been developed, allowing simple isolation of the corresponding free phosphines. The methodology involves the use of pinacol borane (HBpin) to effect the reduction while circumventing the formation of a phosphine borane adduct, as is usually the case with various other commonly used borane reducing agents such as borane tetrahydrofuran complex (BH3?THF) and borane dimethyl sulfide complex (BH3?SMe2). In addition, this methodology requires only a small excess of reducing agent and therefore compares favourably not just with other borane reductants that do not require a metal co-catalyst, but also with silane and aluminium based reagents. (Figure presented.).
- Provis-Evans, Cei B.,Emanuelsson, Emma A. C.,Webster, Ruth L.
-
p. 3999 - 4004
(2018/09/21)
-
- Photo-initiator 2,4,6-trimethylbenzoyldicyclohexyloxyphosphine and preparation method and application thereof
-
The invention relates to a preparation method of a photo-initiator 2,4,6-trimethylbenzoyldicyclohexyloxyphosphine.Under the protection of argon, dicyclohexyl phosphine oxide, metallic sodium and tertiary butanol are reacted in methylbenzene solution to obtain intermediate I; the intermediate I is reacted with 2,4,6-trimethylbenzoyl chloride to obtain intermediate II; the intermediate II is reacted with hydrogen peroxide at 30-35 DEG C to obtain 2,4,6-trimethylbenzoyldicyclohexyloxyphosphine, and liquid phase purity is up to 99.21%.The preparation method is simple to perform and advanced, a solvent is recyclable, and the method is easy for industrial production.
- -
-
Paragraph 0020; 0021
(2016/10/20)
-
- Phosphonium bis(glycolates) and phosphinoglycolates: Synthesis, solvolysis, oxidation to (thio)phosphinoylglycolates and use as ligands in Ni-catalyzed ethylene oligomerization
-
Secondary phosphines, glyoxylic acid hydrate and amines react to form organoammonium phosphonium bis(glycolates) 1a-d. In CD3OD solution, diphenylphosphonium bis(glycolates) undergo reversible solvolysis to phosphinoglycolates 2a,b and acetalic glyoxylic species. The P-dialkyl species 1c avoids this and maintains the phosphonium bis(glycolate) structure in CD 3OD (cHex2P) or undergoes further solvolysis with partial formation of R2PH (R = tBu). Condensation to phosphinoglycines, e.g. 3b, observed for primary amines, does not take place with N-secondary amines at room temperature. Heating leads to condensation but is followed by decarboxylation as shown for the conversion of 2a to 4a. Because of the kinetic lability, the phosphonium compounds 1a-d are sensitive to oxidation by air, H2O2, or sulfur. The resulting phosphinoyl and thiophosphinoyl glycolates and glycolic acids 5-8 are kinetically stable. Precatalyst solutions formed from 1a, c, d and Ni(COD)2 in THF developed moderate to good activity in the oligo- or polymerization of ethylene to linear products containing methyl and vinyl end groups. Activity and molecular weights increased with the +I-effect of the P-substitutents. The solution structures of the novel compounds were elucidated by multinuclear NMR spectroscopy. For 7a a crystal structure analysis is also presented.
- Peulecke, Normen,Kindermann, Markus K.,K?ckerling, Martin,Heinicke, Joachim
-
body text
p. 61 - 69
(2012/08/27)
-
- Reduction of phosphinites, phosphinates, and related species with DIBAL-H
-
Diisobutylaluminium hydride has been found to be an excellent reducing agent for phosphinites, phosphinates, and chlorophosphines. By performing reductions in situ, direct synthesis of secondary phosphine boranes from Grignard reagents has been achieved without isolation or purification of any intermediates. Georg Thieme Verlag Stuttgart.
- Busacca, Carl A.,Bartholomeyzik, Teresa,Cheekoori, Sreedhar,Raju, Ravinder,Eriksson, Magnus,Kapadia, Suresh,Saha, Anjan,Zeng, Xingzhong,Senanayake, Chris H.
-
experimental part
p. 287 - 291
(2009/07/01)
-
- A superior method for the reduction of secondary phosphine oxides
-
(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.
- 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)
-
- A METHOD FOR GENERATING SECONDARY PHOSPHINES
-
This invention provides a method for generating secondary phosphines from secondary phosphine oxides in the presence of a reducing agent, such as diisobutylaluminum hydride (DIBAL-H), triisobutyldialuminoxane, triisobutylaluminum, tetraisobutyldialuminoxane, or another reducing agent comprising: (i) an R1R2AIH moiety, wherein R1 and R2 are each an alkyl species or oxygen, and wherein at least one of R1 or R2 comprises at least 2 carbon atoms, or (ii) an R1R2R3AI moiety, wherein R1, R2, and R3 are not hydrogen, and wherein at least one of R1, R2, and R3 is an alkyl species comprising a β-hydrogen, not including triethylaluminum. Preferred reducing agents for the present invention include: diisobutylaluminum hydride, triisobutyldialiuminoxane, triisobutylaluminum, tetraisobutyldialuminoxane, and combinations thereof.
- -
-
Page/Page column 12-13
(2008/06/13)
-
- Enantioselective addition of secondary phosphines to methacrylonitrile: Catalysis and mechanism
-
A highly enantioselective intermolecular hydrophosphination reaction is described. The (Pigiphos)-nickel(II)-catalyzed reaction of secondary phosphines and methacrylonitrile gives chiral 2-cyanopropylphosphines in good yield and high enantiomeric excess (ee's up to 94%; (R)-(S)-Pigiphos = bis{(R)-1-[(S)-2-(diphenylphosphino)ferrocenyl]ethyl}cyclohexylphos phine). We propose a mechanism involving coordination of methacrylonitrile to the dicationic nickel catalyst followed by 1,4-addition of the phosphine, and then, rate-determining proton transfer. This mechanism is supported by (a) the experimentally determined rate law (rate = K[Ni][methacrylonitrile][t-Bu 2PH]), (b) a large primary deuterium isotope effect K H/KD = 4.6(1) for the addition of t-Bu2PH(D) at 28.3°C in toluene-d8, (c) the isolation and characterization of the species [Ni(K3-Pigiphos)(KN-methacrylonitrile)]2+, and (d) DFT calculations of model compounds.
- Sadow, Aaron D.,Togni, Antonio
-
p. 17012 - 17024
(2007/10/03)
-
- Phosphine and phosphido indium hydride complexes and their use in inorganic synthesis
-
Reaction of PR3, R = cyclohexyl (Cy), cyclopentyl (Cyp) or phenyl, with [lnH3(NMe3)] affords the 1:1 indium trihydride complexes, [InH3(PR3)]. The stabilities and spectroscopic properties of these complexes are described in terms of the phosphine ligands' steric bulk and nucleophilicity. Reaction of two equivalents of PCy3 with [InH3(NMe3)] yields the complex [InH3(PCy3)2] which has been characterised by X-ray crystallography. The first phosphido-indium hydride complex, [{InH2(PCy2)}3], has been prepared by a novel synthetic route which involves treatment of [InH3(NMe3)] with LiPCy2, Its crystal structure shows it to exist as a cyclic trimer in the solid state. The complex, [InH3(PCy3)] has been used to prepare a range of monomeric indium chalcogenolato complexes, [In(EPh)3(PCy3)], E = S, Se or Te, all of which have been structurally characterised. ' The Royal Society of Chemistry 2000.
- Cole, Marcus L.,Hibbs, David E.,Jones, Cameron,Smithies, Neil A.
-
p. 545 - 550
(2007/10/03)
-
- Processes for producing secondary phosphines
-
A process for producing a secondary phosphine of formula (2) wherein R1 and R2 may be the same or different and each represent an alkyl group, a cycloalkyl group or an aryl group, each of the above groups being optionally substituted by an alkyl group, an alkoxy group, a halogen atom, a perfluoroalkyl group, an amino group or a phosphino group, which comprises reacting a phosphine halide of formula (1) wherein R1 and R2 are as defined above and X represents a halogen atom, with a metal selected from the metals of Groups 2 to 15 in the Periodic Table or an alloy thereof and reacting the resultant metal di-substituted phosphide with an agent for protonation.
- -
-
-
- Process for catalytic hydroformylation
-
A novel hydroformylation process for the conversion of olefins having up to about 20 carbon atoms to their corresponding aldehydes is provided herein involving the use of catalysts comprising chelates in which a ligand is chelated at a metal center to produce at least one heterocyclic ring with the central metal atom as part of the ring, i.e., platinum-group metal phosphinoalkylsilyl complexes with bis- or tris(phosphinoalkyl)silyl. Novel catalysts are also provided which are platinum-group metal complexes with bis- or tris(phosphinoalkyl)silyl ligands, which are synthesized by using novel bis(phosphinoalkyl)silanes or tris(phosphinoalkyl)silanes.
- -
-
-
- Phosphido-bridged heterodinuclear complexes of CrPd, MoPd, WPd, and MnPd. X-ray crystal structures of and
-
A series of phosphido-bridged heterodinuclear complexes has been prepared by the low temperature reaction of the labile chain complexes trans-2(PhCN)2> (m = Cr, Mo, W(CO)2Cp; Mn(CO)4) with 3 molar equivalents of PCy2H or PPh2H.The crystal struc
- Braunstein, Pierre,Jesus, Ernesto de,Tiripicchio, Antonio,Camellini, Marisa Tiripicchio
-
-