From isoselectivity to syndioselectivity: Lewis base regulates stereochemistry in 2-vinylpyridine polymerization

2020 ◽  
Vol 11 (20) ◽  
pp. 3434-3438
Author(s):  
Yu Wang ◽  
Jiang-Bing Duan ◽  
Zhao-Xuan Liu ◽  
Tie-Qi Xu
Keyword(s):  
Catalytic System ◽  
Lewis Base ◽  
Effective Synthesis ◽  
System Switching

We have developed an effective synthesis of syndiotactic poly(2-vinylpyridine) by a novel catalytic system. Switching from isoselective to syndioselective polymerization was achieved by adding Lewis base.

scholarly journals Dual metal and Lewis base catalysis approach for asymmetric synthesis of dihydroquinolines and the α-arylation of aldehydes via N-acyliminium ions

2015 ◽  
Vol 51 (87) ◽  
pp. 15788-15791 ◽  
Author(s):  
Chandra M. R. Volla ◽  
Eleonora Fava ◽  
Iuliana Atodiresei ◽  
Magnus Rueping
Keyword(s):  
Asymmetric Synthesis ◽  
Catalytic System ◽  
Optically Active ◽  
Lewis Base ◽  
Base Catalysis ◽  
Asymmetric Addition ◽  
Acyliminium Ions ◽  
Indium Triflate ◽  
Dual Metal

A dual catalytic system consisting of indium triflate and a chiral imidazolidinone catalyzes the asymmetric addition of aldehydes to N-acyl quinoliniums furnishing optically active dihydroquinolines in good yields and excellent selectivities.

Dual Lewis acid - Lewis base activation in enantioselective additions to aldehydes

2006 ◽  
Vol 78 (2) ◽  
pp. 409-414 ◽  
Author(s):  
Erica Wingstrand ◽  
Stina Lundgren ◽  
Maël Penhoat ◽  
Christina Moberg
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Lewis Base ◽  
Direct Route ◽  
Salen Ligands

Reaction of benzaldehyde with ethyl cyanoformate in the presence of Lewis acidic Ti(IV) complexes of bispyridylamide or salen ligands and Lewis basic amines affords the O-alkoxycarbonylated cyanohydrin. In the presence of the salen-based catalytic system, acetyl cyanide can also be added to benzaldehyde, providing a highly enantioselective direct route to the O-acetylated cyanohydrin.

An Efficient Solvent-Free Microwave-Assisted Synthesis of Cinnamamides by Amidation Reaction Using Phenylboronic Acid/Lewis Base Co-catalytic System

Synthesis ◽  
2019 ◽  
Vol 51 (20) ◽  
pp. 3891-3900 ◽  
Author(s):  
Khadidja Khaldoun ◽  
Abdelmounaim Safer ◽  
Salima Saidi-Besbes ◽  
Bertrand Carboni ◽  
Rémy Le Guével ◽  
...  
Keyword(s):  
Catalytic System ◽  
Human Cancer ◽  
Condensation Reaction ◽  
Phenylboronic Acid ◽  
Solvent Free ◽  
Lewis Base ◽  
Microwave Assisted Synthesis ◽  
Cytotoxic Activities ◽  
Microwave Assisted ◽  
Solvent Free Conditions

A microwave-assisted dehydrative amide condensation reaction is reported as an efficient access to cinnamamide derivatives under solvent-free conditions. This protocol between conjugated carboxylic acids and amines is based on the use of a co-catalytic system, including the presence of the commercially available phenylboronic acid and 4-(N,N-dimethylamino)pyridine N-oxide (DMAPO), with a complete chemoselectivity in favor of the corresponding α,β-unsaturated amides. The implementation of the reaction needs no special precaution, and less reactive amines, such as substituted anilines, are also efficient under these conditions. A series of novel conjugated amides have been evaluated for their cytotoxic activities against several human cancer cell lines.

Titanocene dichloride–Lewis base: An efficient catalytic system for coupling of epoxides and carbon dioxide

2009 ◽  
Vol 11 (3) ◽  
pp. 155-157 ◽  
Author(s):  
Dongsheng Bai ◽  
Huanwang Jing ◽  
Qiang Liu ◽  
Qianqian Zhu ◽  
Xiaofang Zhao
Keyword(s):  
Carbon Dioxide ◽  
Catalytic System ◽  
Lewis Base ◽  
Titanocene Dichloride

Effective synthesis of cyclic carbonates from CO2 and epoxides catalyzed by KI/cucurbit[6]uril

2013 ◽  
Vol 85 (8) ◽  
pp. 1633-1641 ◽  
Author(s):  
Jinghua Shi ◽  
Jinliang Song ◽  
Jun Ma ◽  
Zhaofu Zhang ◽  
Honglei Fan ◽  
...  
Keyword(s):  
Propylene Carbonate ◽  
Catalytic System ◽  
Propylene Oxide ◽  
Styrene Oxide ◽  
Synergetic Effect ◽  
Phenyl Ether ◽  
Cyclic Carbonates ◽  
Interesting Topic ◽  
Effective Synthesis ◽  
Potassium Halides

The development of efficient, inexpensive, and nontoxic catalysts for cycloaddition of CO2 with epoxides to produce five-membered cyclic carbonates is a very interesting topic. In this work, cycloaddition of CO2 with propylene oxide (PO) to produce propylene carbonate (PC) catalyzed by potassium halides (KCl, KBr, and KI) in the presence of cucurbit[6]uril (CB[6]) was studied at various conditions. It was discovered that the potassium halides and CB[6] had excellent synergetic effect in promoting the reaction, and the KI/CB[6] catalytic system was the most efficient among them. The decrease of the activity and selectivity of KI/CB[6] was negligible after the catalytic system was reused five times. Further study indicated that the KI/CB[6] catalytic system was also very active and selective for the cycloaddition of CO2 with other epoxides, such as glycidyl phenyl ether, epichlorohydrin, and styrene oxide. The mechanism for the synergetic effect of KI and CB[6] was also discussed.

DFT Study of Lewis Base Interactions with the MgCl2 Surface in the Ziegler−Natta Catalytic System: Expanding the Role of the Donors

2010 ◽  
Vol 114 (37) ◽  
pp. 15771-15781 ◽  
Author(s):  
Kumar Vanka ◽  
Gurmeet Singh ◽  
Divya Iyer ◽  
Virendra K. Gupta
Keyword(s):  
Catalytic System ◽  
Lewis Base ◽  
Dft Study

scholarly journals Synergistic effects in ambiphilic phosphino-borane catalysts for the hydroboration of CO2

2016 ◽  
Vol 52 (48) ◽  
pp. 7553-7555 ◽  
Author(s):  
Anis Tlili ◽  
Arnaud Voituriez ◽  
Angela Marinetti ◽  
Pierre Thuéry ◽  
Thibault Cantat
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Synergistic Effects ◽  
Lewis Base

The benefit of combining both a Lewis acid and a Lewis base in a catalytic system has been established for the hydroboration of CO2, using ferrocene-based phosphine, borane and phosphino-borane derivatives.

Molecular evolution of a cytochrome P450 for the synthesis of potential antidepressant (2R,6R)-hydroxynorketamine

2021 ◽  
Author(s):  
Ansgar Bokel ◽  
Michael C. Hutter ◽  
Vlada B. Urlacher
Keyword(s):  
Cytochrome P450 ◽  
Molecular Evolution ◽  
Cytochrome P450 Monooxygenase ◽  
P450 Monooxygenase ◽  
Effective Synthesis

Engineered cytochrome P450 monooxygenase CYP154E1 enables the effective synthesis of the potential antidepressant (2R,6R)-hydroxynorketamine via N-demethylation and regio- and stereoselective hydroxylation of (R)-ketamine.

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