Eu(Ⅲ) complexes involving 1,3,5-triazine diphosphine oxides

The 1,3,5-triazine diphosphine oxide ligands with donor-acceptor properties formed strong complexes with europium（Ⅲ） ion in acetonitrile. Spectrophotometric titrations and mass spectra indicated that two ligands coordinated to one europium ion. The stability constants varied from 11.64 to 14.60 （log 13）. Binary complexes exhibited rather weak luminescence in solution. 1,3,5-triazine diphosphine oxides engaged as co-ligands in Eu（Ⅲ） （2-thenoyltrifluoroacetonate）3 complex contributed to the overall photoluminescence and allowed for excitation with longer wavelengths than the parent complex.

Asymmetric hydrogenation of aromatic ketones using new chiral-bridged diphosphine/diamine-Ru(Ⅱ) complexes

A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new（（Rax）-BuP）/（R,R）-DPEN-Ru（Ⅱ） complex catalyst system.The hydrogenation of 2-methylacetophenone in n-butanol （t-BuOK/Ru =45.6/1,S/C = 500,20 atm.of H2,20℃,48 h） afforded（S）-1-（2＇-methylphenyl）ethanol in 92%ee and〉99% conversion.

The Performance of Rhodium Complex-diphosphine Systems in the Hydroformylation of 1-Dodecene

The catalytic performances of four HRh(CO)(PPh3)3-diphosphine (BISBI,BDPX, BDNA and BINAP) systems in 1-dodecene hydroformylation were investigated and compared with HRh(CO)(PPh3)3-PPh3 system. The catalyst system HRh(CO)(PPh3)3-BISBI exhibited very high regioselectivity for the formation of linear aldehyde.

Design and synthesis of novel 1,3-diene bridged chiral atropoisomeric diphosphine ligands for asymmetric hydrogenation ofα-dehydro amino ketones

A series of novel atropisomeric diphosphine ligands termed Tan Phos were designed and synthesized,which has a smaller bite angle compared with that of other ligands such as BINAP.Tan Phos showed high reactivity and enantioselectivity in the rhodiumcatalyzed asymmetric hydrogenation ofα-dehydro amino ketones,and up 99%yield and 99%ee were obtained for a wide range of chiralα-amino ketones.

Highly Enantioselective Hydrogenation of tetra-and tri-Substitutedα,β-Unsaturated Carboxylic Acids with oxa-Spiro Diphosphine Ligands

We herein present the design and synthesis of a structurally unique oxa-spirocyclic diphosphine ligand,termed as O-SDP.The diphosphine ligand O-SDP derived from oxa-spirocyclic diphenols(O-SPINOL)has a relatively larger bite angle compared with that of SDP,and O-SDP has been successfully applied in the ruthenium-catalyzed asymmetric hydrogenation ofα,β-unsaturated carboxylic acids under mild reaction conditions.High yields and enantioselectivities were generally achieved for a wide range of substrates(up to 99%yield and>99%ee),and many of the resulting products are key intermediates of important drugs such as Sacubitril,Artemisinin,and Paroxetine.

Synthesis of New MeO-BIPHEP-type Chiral Diphosphines by an Improved Way

In this paper, a series of new optically active MeO-BIPHEP-type ligands, （S）-6,6＇-dimethoxy-2,2＇-bis（dip-alkoxyphenyl-phosphine）-l,l＇-biphenyl [（S）-5b-（S）-5e] were prepared and characterized. Starting from the commercially available triethyl phosphorite and m-bromoanisole, an optically active （S）-6,6＇-dimethoxybiphenyl- 2,2＇-diyl-bis（phosphonic acid diester） was prepared by an improved way and converted to the corresponding dichlorides, which was used as a key intermediate to react with p-alkoxybenzenemagnesium bromide or p-alkoxyphenyl lithium to directly give the enantiomerically pure diphosphines 5.

Diphosphine mediated assembly of multinuclear silver complexes containing the thiolato ligand 2-mercaptobenzoxazole(Hmbo)

A new complex [AG4(μ2-S-Mbo)4(dppp)4)](1) is obtained from the reaction of AgBF4 and Hmbo(2-mercaptobenzoxazole) with the participation of dppp(bis(diphenylphosphino) propane). Single crystal X-ray diffraction analysis shows that it is discrete neutral molecule and composed of two asymmetrical moieties. Four Ag atoms in each molecule are completely coplanar and of similar environment. The ligands Hmbo and dppp in complex 1 bridge two Ag atoms through 'μ2-S -mbo' and P atoms in two ends, respectively. The possible mechanism of the reaction is provided, and the sequence of adding materials and the length of backbone (CH2)n in diphosphine play an important role in the results of the reactions.

Facile Synthesis of Chiral Diphosphine-Containing Multiple Dendrimeric Catalysts for Enantioselective Hydrogenation

A new kind of chiral diphosphine PyrPhos-functionalized codendrimers have been synthesized via a liq- uid-phase strategy in high yields. The resulting dendrimeric PyrPhos ligands were purified by a simple solvent pre- cipitation without the need for chromatographic separation, and well characterized by 1H, 13C and 31p NMR, MALDI-TOF mass spectroscopy as well as elemental analysis. Their rhodium complexes were applied to the asymmetric hydrogenation of a-acetamido cinnamic acids. Excellent enantioselectivities were achieved, which are comparable to those with the corresponding small molecular catalysts. In addition, these codendrimeric catalysts showed better catalytic performance than the dendrimeric catalysts with Rh（PyrPhos） sites located in the focal point ofpoly（aryl ether） dendrons or in the periphery ofpoly（propyleneimine） dendrimers.

A Novel Octanuclear Molecular Loop Formed by Linkage of Oxo-centered Triruthenium Cluster Units

A novel dimeric complex [Ru3 (μ3-O)(μ-CH3COO)(CO)]2(μ-dppf)(μ-odppf)(dppf = 1, 1'-bis(diphenylphosphio)ferrocene, odppf = 1, 1'-bis(oxodiphenylphosphoranyl)ferrocene) (1) of oxo-centered triruthenium-aectate cluster units was synthesized and characterized by X-ray crystallography. Compound 1 exhibits a cyclic structure formed by linkages of two triruthenium cluster units Ru3 (μ3-O)(μ-CH3COO)6(CO) through dppf and odppf ligands, respectively. The diameter of the molecular loop is ca. 1.0 nm.

Enantioselective and a-Regioselective Allylic Amination of Morita-Baylis-Hillman Acetates with Simple Aromatic Amines Catalyzed by Planarly Chiral Ligand/Palladium Catalyst

An asymmetric allylic amination of Morita-Baylis-Hillman acetates with simple aromatic amines catalyzed by planarly chiral ligand/palladium-catalyst was developed in good yield with excellent a-regioselectivity （a/γ up to 30 ： 1） and moderate enantioselectivity （up to 70% ee）.

Rhodium catalyzed asymmetric Pauson-Khand reaction using SDP ligands

The activity and enantiocontrol ability of the chiral catalysts prepared from spiro di-phosphine ligands, SDP, and rhodium precursor were investigated in the asymmetric catalytic Pau-son-Khand reaction. The results showed that SDP ligands were very effective in Rh-catalyzed Pau-son-Khand reaction, and their complexes with rhodium could convert a variety of 1,6-enyne compounds into bicyclopentone derivatives under CO atmosphere in high yields with good enantioselec-tivities. The SbF6- was found to be a suitable counter anion of the catalyst, and 1,2-dichloroethane was the best choice of the solvent for Pauson-Khand reaction.

Synthesis, Characterization and Electrochemistry of 1,2-Bis(diphenylphosphino)benzene-chelated Diiron Ethane-1,2-dithiolate Tetracarbonyl Complex

In this paper,a novel diiron ethane-1,2-dithiolate complex[Fe2(CO)4{κ2-(Ph2P)2(1,2-C6H4)}(μ-SCH2CH2S)]has been prepared and structurally characterized.Treatment of the parent complex[Fe2(CO)6(μ-SCH2CH2S)]with 1 equivalent of 1,2-bis(diphenylphosphino)benzene and Me3NO?2H2O as the oxidative agent gave the title complex in good yield.The title complex has been characterized by elemental analysis,IR,1H NMR,31P{1H}NMR,13C{1H}NMR spectroscopy,and X-ray crystallography.X-ray crystal structure of the title complex contains a butterfly diiron cluster with a bridging ethane-1,2-dithiolate,four terminal carbonyls,and a chelating 1,2-bis(diphenylphosphino)benzene.In addition,electrochemical studies revealed that the title complex can catalyze the reduction of protons to H2 in the presence of acetic acid.