Remarkable Electronic and Steric Effects in the Nitrile Biotransformations for the Preparation of Enantiopure Functionalized Carboxylic Acids and Amides:  Implication for an Unsaturated Carbon−Carbon Bond Binding Domain of the Amidase

2007 ◽  
Vol 72 (16) ◽  
pp. 6060-6066 ◽  
Author(s):  
Ming Gao ◽  
De-Xian Wang ◽  
Qi-Yu Zheng ◽  
Zhi-Tang Huang ◽  
Mei-Xiang Wang
Keyword(s):  
Carboxylic Acids ◽  
Binding Domain ◽  
Steric Effects ◽  
Carbon Bond ◽  
Carbon Carbon Bond ◽  
Electronic And Steric Effects

Studies on Iron-Catalyzed Aerobic Oxidation of Benzylic Alcohols to Carboxylic Acids

Synthesis ◽  
2018 ◽  
Vol 50 (08) ◽  
pp. 1629-1639 ◽  
Author(s):  
Shengming Ma ◽  
Xingguo Jiang
Keyword(s):  
Carboxylic Acids ◽  
Large Scale ◽  
Aerobic Oxidation ◽  
Catalytic Amount ◽  
Steric Effects ◽  
Benzylic Alcohols ◽  
Academic Laboratory ◽  
Electron Donating Groups ◽  
Electronic And Steric Effects ◽  
Comprehensive Study

A comprehensive study on aerobic oxidation of benzylic alcohols­ to carboxylic acids with a catalytic amount each of Fe(NO3)3·9H2O, TEMPO, and KCl is conducted. Various synthetically useful functional groups are well tolerated in the reaction. Distinct electronic and steric effects are observed in the reaction: electron-withdrawing groups accelerate the reaction while electron-donating groups make the reaction slower, and ortho-substituted substrates react slower than meta-substituted substrates. Several large-scale reactions (100 mmol) are conducted using a slow air flow of 30 mL/min to demonstrate the practicality of this method in an academic laboratory.

scholarly journals Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids

2020 ◽  
Author(s):  
Zi-Qi Li ◽  
Yue Fu ◽  
Ruohan Deng ◽  
Van Tran ◽  
Yang Gao ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Transition State ◽  
Carboxylic Acids ◽  
Alkyl Group ◽  
Steric Effects ◽  
High Yield ◽  
Mechanistic Studies ◽  
Ligand Environment ◽  
Ligand Free ◽  
Electronic And Steric Effects

<div>A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99% yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state. <br></div>

Deoxygenative Transformation of Carbonyl and Carboxyl Compounds Using gem-Diborylalkanes

Synlett ◽  
2019 ◽  
Vol 30 (10) ◽  
pp. 1105-1110 ◽  
Author(s):  
Yue Hu ◽  
Wei Sun ◽  
Chao Liu
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Carbon Bond ◽  
Recent Advances ◽  
Carbon Carbon Bond ◽  
Efficient Construction

gem-Diborylalkanes serve as privileged carbanion precursors for the efficient construction of carbon–carbon bond with various carbonyl and carboxyl compounds. We highlight the recent advances on deoxygenative transformation of carbonyl and carboxyl compounds using gem-diborylalkanes reagents. Our recent development of a dual functionalization of gem-diborylalkanes through deoxygenative enolization with the carboxylic acids is also discussed.1 Introduction2 Activation Modes of gem-Diborylalkanes3 Deoxygenative Transformation of Carbonyl and Carboxyl ­Compounds via α-Diboryl Carbanion3.1 Reaction with Aldehyde and Ketone Electrophiles3.2 Reaction with Carboxylic Acid Derivatives4 Deoxygenative Transformation of Carbonyl and Carboxyl ­Compounds via α-Monoboryl Carbanion5 Conclusion

scholarly journals Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids

2020 ◽  
Author(s):  
Zi-Qi Li ◽  
Yue Fu ◽  
Ruohan Deng ◽  
Van Tran ◽  
Yang Gao ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Transition State ◽  
Carboxylic Acids ◽  
Alkyl Group ◽  
Steric Effects ◽  
High Yield ◽  
Mechanistic Studies ◽  
Ligand Environment ◽  
Ligand Free ◽  
Electronic And Steric Effects

<div>A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99% yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state. <br></div>

Sign in / Sign up

Export Citation Format

Share Document