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).

Copper-catalyzed 1,6-conjugate addition of para-quinone methides with diborylmethane

2021 ◽  
Author(s):  
Xin Li ◽  
Guoliang Gao ◽  
Songtao He ◽  
Qiuling Song
Keyword(s):  
Catalytic System ◽  
Conjugate Addition ◽  
Quinone Methides ◽  
High Yields

Presented herein is the first 1,6-conjugate addition of diborylmethane, which is promoted by a simple and inexpensive copper catalytic system. This method features high yields, good selectivities and broad functional...

scholarly journals A two step synthesis of a key unit B precursor of cryptophycins by asymmetric hydrogenation

2011 ◽  
Vol 7 ◽  
pp. 243-245 ◽  
Author(s):  
Benedikt Sammet ◽  
Mathilde Brax ◽  
Norbert Sewald
Keyword(s):  
Asymmetric Hydrogenation ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
High Yields

A novel highly enantioselective two step access to a unit B precursor of cryptophycins in good yields from commercially available starting materials has been developed. The key step is an asymmetric hydrogenation using the commercially available [(COD)Rh-(R,R)-Et-DuPhos]BF4 catalyst. The synthetic route provides the advantage of less synthetic steps, proceeds with high yields and enantioselectivity, and avoids hazardous reaction conditions.

Manganese-Catalyzed Enantioselective Hydrogenation of Simple Ketones Using an Imidazole-Based Chiral PNN Tridentate Ligand

Synlett ◽  
2020 ◽  
Vol 31 (03) ◽  
pp. 285-289 ◽  
Author(s):  
Fei Ling ◽  
Jiachen Chen ◽  
Sanfei Nian ◽  
Huacui Hou ◽  
Xiao Yi ◽  
...  
Keyword(s):  
Functional Group ◽  
Asymmetric Hydrogenation ◽  
Enantioselective Hydrogenation ◽  
Tridentate Ligand ◽  
Easy Access ◽  
Tridentate Ligands

A series of Mn(I) catalysts containing imidazole-based chiral PNN tridentate ligands with controllable ‘side arm’ groups have been established, enabling the inexpensive base-promoted asymmetric hydrogenation of simple ketones with outstanding activities (up to 8200 TON) and good enantioselectivities (up to 88.5% ee). This protocol features wide substrate scope and functional group tolerance, thereby providing easy access to a key intermediate of crizotinib.

A Mild Dihydrobenzooxaphosphole Oxazoline/Iridium Catalytic System for Asymmetric Hydrogenation of Unfunctionalized Dialins

2014 ◽  
Vol 53 (52) ◽  
pp. 14428-14432 ◽  
Author(s):  
Bo Qu ◽  
Lalith P. Samankumara ◽  
Shengli Ma ◽  
Keith R. Fandrick ◽  
Jean-Nicolas Desrosiers ◽  
...  
Keyword(s):  
Catalytic System ◽  
Asymmetric Hydrogenation

Enantioselective hydrogenation of N-heteroaromatics catalyzed by chiral diphosphine modified binaphthyl palladium nanoparticles

2017 ◽  
Vol 7 (23) ◽  
pp. 5515-5520 ◽  
Author(s):  
Yun-Tao Xia ◽  
Jing Ma ◽  
Xiao-Dong Wang ◽  
Lei Yang ◽  
Lei Wu
Keyword(s):  
Palladium Nanoparticles ◽  
Asymmetric Hydrogenation ◽  
Enantioselective Hydrogenation

The first application of binaphthyl-stabilized palladium nanoparticles (Bin-PdNPs) with chiral modifiers in asymmetric hydrogenation of N-heteroaromatics is revealed.

scholarly journals P2O5/SiO2as an Efficient, Green and Heterogeneous Catalytic System for the Solvent-Free Synthesis of 3,4-Dihydropyrimidin-2-(1H)-ones (and -Thiones)

2009 ◽  
Vol 6 (2) ◽  
pp. 459-465 ◽  
Author(s):  
Alireza Hasaninejad ◽  
Abdolkarim Zare ◽  
Farhad Jafari ◽  
Ahmad Reza Moosavi-Zare
Keyword(s):  
Catalytic System ◽  
Catalytic Amount ◽  
Solvent Free ◽  
Heterogeneous Catalytic ◽  
Heterogeneous Catalytic System ◽  
High Yields ◽  
Solvent Free Synthesis

A simple, green and efficient solventless procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones (and -thiones) from aldehydes, β-ketoesters and urea or thiourea in the presence of catalytic amount of silica-supported P2O5(P2O5/SiO2) at 85 °C is described. Using this method, the title compounds were produced in high yields.

Asymmetric Synthesis of Chiral δ-lactones using BINAP-ruthenium(II) Complexes Hydrogenation Catalysts

2002 ◽  
Vol 2002 (11) ◽  
pp. 567-569 ◽  
Author(s):  
Yanjun Li ◽  
Taeko Izumi
Keyword(s):  
Asymmetric Synthesis ◽  
Ruthenium Complexes ◽  
Asymmetric Hydrogenation ◽  
Optical Purity ◽  
Hydrogenation Catalysts ◽  
Keto Acids ◽  
Chiralcel Od ◽  
High Yields

Asymmetric hydrogenation of keto-acids was accomplished by catalytic amounts of BINAP-ruthenium complexes to afford the corresponding δ-lactones in high yields. The optical purity of the synthesised δ-lactones was determined by chiralcel (OD) in the 9–56% range.

Pd(0)–PhCOOH catalyzed addition of oxygen pronucleophiles to allenes and internal alkynes

2005 ◽  
Vol 83 (6-7) ◽  
pp. 569-573 ◽  
Author(s):  
Nitin T Patil ◽  
Nirmal K Pahadi ◽  
Yoshinori Yamamoto
Keyword(s):  
Benzoic Acid ◽  
Carboxylic Acids ◽  
Catalytic System ◽  
Addition Reaction ◽  
Internal Alkynes ◽  
High Yields

We have developed a catalytic system that enables the addition of alcohols to allenes using a combination of 5 mol% Pd(PPh3)4 and 10 mol% benzoic acid. Likewise, the addition reaction of carboxylic acids to alkynes is described. In all cases the reaction proceeded well, giving the corresponding allylation products in good-to-high yields with high regio- and stereoselectivities.Key words: addition, alcohols, carboxylic acids, allenes, alkynes, palladium.

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