A Platform for Decarboxylative Couplings via Photoredox Catalysis: Direct Access to Carbocations from Carboxylic Acids for Carbon–Oxygen Bond Formation

ACS Catalysis ◽  
2021 ◽  
pp. 10997-11004
Author(s):  
Peijun Li ◽  
Jason R. Zbieg ◽  
Jack A. Terrett
Keyword(s):  
Carboxylic Acids ◽  
Bond Formation ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Oxygen Bond

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

Generation of Phosphoranyl Radicals via Photoredox Catalysis Enables Voltage–Independent Activation of Strong C–O Bonds

2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle
Keyword(s):  
Carboxylic Acids ◽  
Functional Groups ◽  
Single Step ◽  
Direct Access ◽  
Photoredox Catalysis ◽  
Acyl Radical ◽  
Synthetic Strategy ◽  
Acyl Radicals ◽  
Benzyl Radicals ◽  
Aliphatic Carboxylic Acids

Alcohols and carboxylic acids are ubiquitous functional groups found in organic molecules that could serve as radical precursors, but C–O bonds remain difficult to activate. We report a synthetic strategy for direct access to both alkyl and acyl radicals from these ubiquitous functional groups via photoredox catalysis. This method exploits the unique reactivity of phosphoranyl radicals, generated from a polar/SET crossover between a phosphine radical cation and an oxygen centered nucleophile. We first show the desired reactivity in the reduction of benzylic alcohols to the corresponding benzyl radicals with terminal H-atom trapping to afford the deoxygenated product. Using the same method, we demonstrate access to synthetically versatile acyl radicals which enables the reduction of aromatic and aliphatic carboxylic acids to the corresponding aldehydes with exceptional chemoselectivity. This protocol also transforms carboxylic acids to heterocycles and cyclic ketones via intramolecular acyl radical cyclizations to forge new C–O, C–N and C–C bonds in a single step.

Organocatalytic Electrochemical C–H Lactonization of Aromatic Carboxylic Acids

Synthesis ◽  
2018 ◽  
Vol 50 (15) ◽  
pp. 2924-2929 ◽  
Author(s):  
Sanzhong Luo ◽  
Longji Li ◽  
Qi Yang ◽  
Zongbin Jia
Keyword(s):  
Carboxylic Acid ◽  
Carboxylic Acids ◽  
Glassy Carbon ◽  
Bond Formation ◽  
Carbon Electrodes ◽  
Glassy Carbon Electrodes ◽  
Aromatic Carboxylic Acids ◽  
Radical Substitution ◽  
Carboxyl Radical ◽  
Oxygen Bond

An electrochemical strategy has been developed for radical arene carbon–oxygen bond formation. This reaction utilizes DDQ as a redox mediator, with inexpensive glassy carbon electrodes to facilitate an intramolecular lactonization of biphenyl-2-carboxylic acid derivatives via aromatic carboxyl radical substitution to give 6H-benzo[c]chromen-6-ones.

Formation of Carbon-Oxygen Bond Mediated by Hypervalent Iodine Reagents Under Metal-free Conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  
Keyword(s):  
Natural Products ◽  
Bond Formation ◽  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Metal Free ◽  
Bioactive Natural Products ◽  
The Past ◽  
Oxygen Bond ◽  
Privileged Scaffolds

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions

scholarly journals Fast Carbon Isotope Exchange of Carboxylic Acids Enabled by Organic Photoredox Catalysis

2021 ◽  
Vol 143 (5) ◽  
pp. 2200-2206
Author(s):  
Duanyang Kong ◽  
Maxime Munch ◽  
Qiqige Qiqige ◽  
Christopher J. C. Cooze ◽  
Benjamin H. Rotstein ◽  
...  
Keyword(s):  
Carbon Isotope ◽  
Carboxylic Acids ◽  
Isotope Exchange ◽  
Photoredox Catalysis

ChemInform Abstract: New Access to H-Phosphonates via Metal-Catalyzed Phosphorus—Oxygen Bond Formation.

ChemInform ◽  
2008 ◽  
Vol 39 (1) ◽  
Author(s):  
Laetitia Coudray ◽  
Isabelle Abrunhosa-Thomas ◽  
Jean-Luc Montchamp
Keyword(s):  
Bond Formation ◽  
Metal Catalyzed ◽  
Oxygen Bond

A computational study on the mechanism of ynamide-mediated amide bond formation from carboxylic acids and amines

2017 ◽  
Vol 15 (30) ◽  
pp. 6367-6374 ◽  
Author(s):  
Song-Lin Zhang ◽  
Hai-Xing Wan ◽  
Zhu-Qin Deng
Keyword(s):  
Reaction Mechanism ◽  
Carboxylic Acids ◽  
Computational Study ◽  
Bond Formation ◽  
Amide Bond ◽  
Reactivity Pattern ◽  
Amide Bond Formation ◽  
Coupling Reagent ◽  
Catalytic Effects ◽  
Acid Substrate

A detailed computational study is presented on the reaction mechanism of ynamide-mediated condensation of carboxylic acids with amines to produce amides, which elucidates the reactivity pattern of the coupling reagent ynamide and discloses crucial bifunctional catalytic effects of the carboxylic acid substrate during aminolysis.

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