scholarly journals A supramolecularly tunable chiral diphosphine ligand: application to Rh and Ir-catalyzed enantioselective hydrogenation

2016 ◽  
Vol 7 (7) ◽  
pp. 4594-4599 ◽  
Author(s):  
Xi-Chang Zhang ◽  
Yi-Hu Hu ◽  
Chuan-Fu Chen ◽  
Qiang Fang ◽  
Li-Yao Yang ◽  
...  
Keyword(s):  
Crown Ethers ◽  
Enantioselective Hydrogenation ◽  
Diphosphine Ligand ◽  
Asymmetric Hydrogenations ◽  
High Yields ◽  
Chiral Bisphosphine Ligand

A supramolecularly tunable chiral bisphosphine ligand bearing two pyridyl-containing crown ethers was synthesized and applied in Rh or Ir-catalyzed asymmetric hydrogenations in high yields with excellent ee values (90–99% ee).

Rhodium/bisphosphine-thiourea-catalyzed enantioselective hydrogenation of α,β-unsaturated N-acylpyrazoles

2016 ◽  
Vol 52 (78) ◽  
pp. 11677-11680 ◽  
Author(s):  
Pan Li ◽  
Xinquan Hu ◽  
Xiu-Qin Dong ◽  
Xumu Zhang
Keyword(s):  
Catalytic System ◽  
Asymmetric Hydrogenation ◽  
Enantioselective Hydrogenation ◽  
High Yields

We successfully extended our Rh/bisphosphine-thiourea (ZhaoPhos) catalytic system to asymmetric hydrogenation of α,β-unsaturated N-acylpyrazoles affording products with high yields and excellent enantioselectivities (up to 97% yield, 99% ee).

scholarly journals Continuous-flow catalytic asymmetric hydrogenations: Reaction optimization using FTIR inline analysis

2012 ◽  
Vol 8 ◽  
pp. 300-307 ◽  
Author(s):  
Magnus Rueping ◽  
Teerawut Bootwicha ◽  
Erli Sugiono
Keyword(s):  
Continuous Flow ◽  
Flow Cell ◽  
Reaction Monitoring ◽  
Reaction Parameters ◽  
Reaction Optimization ◽  
Catalytic Asymmetric ◽  
Asymmetric Hydrogenations ◽  
High Yields ◽  
Flow Microreactors

The asymmetric organocatalytic hydrogenation of benzoxazines, quinolines, quinoxalines and 3H-indoles in continuous-flow microreactors has been developed. Reaction monitoring was achieved by using an inline ReactIR flow cell, which allows fast and convenient optimization of reaction parameters. The reductions proceeded well, and the desired products were isolated in high yields and with excellent enantioselectivities.

ChemInform Abstract: A Supramolecularly Tunable Chiral Diphosphine Ligand: Application to Rh and Ir-Catalyzed Enantioselective Hydrogenation.

ChemInform ◽  
2016 ◽  
Vol 47 (45) ◽  
Author(s):  
Xi-Chang Zhang ◽  
Yi-Hu Hu ◽  
Chuan-Fu Chen ◽  
Qiang Fang ◽  
Li-Yao Yang ◽  
...  
Keyword(s):  
Enantioselective Hydrogenation ◽  
Diphosphine Ligand

Enantioselective Transfer Hydrogenation of Oxocarbenium Ions Enables Asymmetric Access to α-Substituted 1,3-Dihydroisobenzofurans

Synthesis ◽  
2021 ◽  
Author(s):  
Lei Liu ◽  
Likai Zhou ◽  
Kuiyong Jia ◽  
xigong Liu
Keyword(s):  
Enantioselective Hydrogenation ◽  
Transfer Hydrogenation ◽  
Oxocarbenium Ions ◽  
High Yields

Reported here is an efficient enantioselective hydrogenation of cyclic oxocarbenium ions generated in situ through collapse of corresponding acetal substrates. The asymmetric approach provides a straightforward access to a variety of chiral α-aryl substituted 1,3-dihydroisobenzofurans in high yields with excellent enantioselectivities.α-Alkynyl substituted 1,3-dihydroisobenzofurans were also proved to be suitable substrates. In addition, when the reaction was performed at gram scale, the desired product was obtained in good yields with excellent enantioselectivity.

scholarly journals Enantioselective synthesis of 3-substituted dihydrobenzofurans through iridium-catalyzed intramolecular hydroarylation

2021 ◽  
Author(s):  
Kana Sakamoto ◽  
Takahiro Nishimura
Keyword(s):  
Enantioselective Synthesis ◽  
Iridium Complex ◽  
High Yields ◽  
Chiral Bisphosphine Ligand

The enantioselective cyclization was efficiently catalyzed by a cationic iridium complex coordinated with a conventional chiral bisphosphine ligand to give benzofurans in high yields with high enantioselectivity.

scholarly journals Diastereomeric control of enantioselectivity: evidence for metal cluster catalysis

2014 ◽  
Vol 50 (57) ◽  
pp. 7705-7708 ◽  
Author(s):  
Ahmed F. Abdel-Magied ◽  
Amrendra K. Singh ◽  
Matti Haukka ◽  
Michael G. Richmond ◽  
Ebbe Nordlander
Keyword(s):  
General Formula ◽  
Metal Cluster ◽  
Enantioselective Hydrogenation ◽  
Diphosphine Ligand ◽  
Tiglic Acid

Enantioselective hydrogenation of tiglic acid effected by diastereomers of the general formula [(μ-H)2Ru3(μ3-S)(CO)7(μ-P–P*)] (P–P* = chiral Walphos diphosphine ligand) strongly supports catalysis by intact Ru3 clusters.

A Simple Method for Preparing Fibrinogen

1966 ◽  
Vol 16 (01/02) ◽  
pp. 198-206 ◽  
Author(s):  
W Straughn ◽  
R. H Wagner
Keyword(s):  
Barium Sulfate ◽  
Caproic Acid ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Human Fibrinogen ◽  
Simple Method ◽  
High Yields ◽  
Marked Stability

SummaryA simple new procedure is reported for the isolation of canine, bovine, porcine, and human fibrinogen. Two molar β-alanine is used to precipitate fibrinogen from barium sulfate adsorbed plasma. The procedure is characterized by dependability and high yields. The material is 95% to 98% clottable protein but still contains impurities such as plasminogen and fibrin-stabilizing factor. Plasminogen may be removed by adsorption with charcoal. The fibrinogen preparations exhibit marked stability to freezing, lyophilization, and dialysis. Epsilon-amino-n-caproic acid and gamma-aminobutyric acid which were also studied have the property of precipitating proteins from plasma but lack the specificity for fibrinogen found with β-alanine.

A Novel Method for the Rapid Purification of Human and Rat Fibrin(OGEN) Degradation Products in High Yields

1979 ◽  
Author(s):  
W. Nieuwenhuizen ◽  
I. A. M. van Ruijven-Vermeer ◽  
F. Haverkate ◽  
G. Timan
Keyword(s):  
Degradation Products ◽  
Complete Separation ◽  
Purification Method ◽  
Amino Terminal ◽  
Novel Method ◽  
Rapid Purification ◽  
The One ◽  
High Yields ◽  
Size Heterogeneity ◽  
D Dimer

A novel method will be described for the preparation and purification of fibrin(ogen) degradation products in high yields. The high yields are due to two factors. on the one hand an improved preparation method in which the size heterogeneity of the degradation products D is strongly reduced by plasmin digestion at well-controlled calcium concentrations. At calcium concentrations of 2mM exclusively D fragments, M.W.= 93-000 (Dcate) were formed; in the presence of 1OmM EGTA only fragments M.W.= 80.000 (D EGTA) were formed as described. on the other hand a new purification method, which includes Sephadex G-200 filtration to purify the D:E complexes and separation of the D and E fragments by a 16 hrs. preparative isoelectric focussing. The latter step gives a complete separation of D (fragments) (pH = 6.5) and E fragments (at pH = 4.5) without any overlap, thus allowing a nearly 100% recovery in this step. The overall recoveries are around 75% of the theoretical values. These recoveries are superior to those of existing procedures. Moreover the conditions of this purification procedure are very mild and probably do not affect the native configuration of the products. Amino-terminal amino acids of human Dcate, D EGTA and D-dimer are identical i.e. val, asx and ser. in the ratgly, asx and ser were found. E 1% for rat Dcate=17-8 for rat D EGTA=16.2 and for rat D- dimer=l8.3. for the corresponding human fragments, these values were all 20.0 ± 0.2.

Studi Awal Geologi di Daerah Beruang Kanan Kabupaten Gunung Mas Propinsi Kalimantan Tengah

PROMINE ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1-11
Author(s):  
Retno Anjarwati ◽  
Arifudin Idrus ◽  
Lucas Donny Setijadji
Keyword(s):  
Gold Mineralization ◽  
Volcanic Rocks ◽  
Gold Deposits ◽  
Central Kalimantan ◽  
Magmatic Arc ◽  
Tertiary Sediment ◽  
Copper Gold ◽  
Regional Tectonic ◽  
Mineralization Processes ◽  
High Yields

The regional tectonic conditions of the KSK Contract of Work are located in the mid-Tertiary magmatic arc (Carlile and Mitchell, 1994) which host a number of epithermal gold deposits (eg, Kelian, Indon, Muro) and significant prospects such as Muyup, Masupa Ria, Gunung Mas and Mirah. Copper-gold mineralization in the KSK Contract of Work is associated with a number of intrusions that have occupied the shallow-scale crust at the Mesozoic metamorphic intercellular junction to the south and continuously into the Lower Tertiary sediment toward the water. This intrusion is interpreted to be part of the Oligocene arc of Central Kalimantan (in Carlile and Mitchell 1994) Volcanic rocks and associated volcanoes are older than intrusions, possibly aged Cretaceous and exposed together with all three contacts (Carlile and Mitchell, 1994) some researchers contribute details about the geological and mineralogical background, and some papers for that are published for the Beruang Kanan region and beyond but no one can confirm the genesis type of the Beruang Kanan region The mineralization of the Beruang Kanan area is generally composed by high yields of epithermal sulphide mineralization. with Cu-Au mineralization This high epithermal sulphide deposition coats the upper part of the Cu-Au porphyry precipitate associated with mineralization processes that are generally controlled by the structure

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