Mechanistic Study on the Decarboxylative sp3 C–N Cross-Coupling between Alkyl Carboxylic Acids and Nitrogen Nucleophiles via Dual Copper and Photoredox Catalysis

2019 ◽  
Vol 58 (19) ◽  
pp. 12669-12677 ◽  
Author(s):  
Xia Zhao ◽  
Yanhong Liu ◽  
Rongxiu Zhu ◽  
Chengbu Liu ◽  
Dongju Zhang
2019 ◽  
Vol 6 (14) ◽  
pp. 2365-2370 ◽  
Author(s):  
Hui Yang ◽  
Chao Tian ◽  
Dongsheng Qiu ◽  
Haitao Tian ◽  
Guanghui An ◽  
...  

The first redox neutral decarboxylative alkylation of gem-difluoroalkenes via C–F bond activation enabled by organic photoredox catalysis has been developed.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Leitao Huan ◽  
Xiaomin Shu ◽  
Weisai Zu ◽  
De Zhong ◽  
Haohua Huo

AbstractAsymmetric C(sp3)−H functionalization is a persistent challenge in organic synthesis. Here, we report an asymmetric benzylic C−H acylation of alkylarenes employing carboxylic acids as acyl surrogates for the synthesis of α-aryl ketones via nickel and photoredox dual catalysis. This mild yet straightforward protocol transforms a diverse array of feedstock carboxylic acids and simple alkyl benzenes into highly valuable α-aryl ketones with high enantioselectivities. The utility of this method is showcased in the gram-scale synthesis and late-stage modification of medicinally relevant molecules. Mechanistic studies suggest a photocatalytically generated bromine radical can perform benzylic C−H cleavage to activate alkylarenes as nucleophilic coupling partners which can then engage in a nickel-catalyzed asymmetric acyl cross-coupling reaction. This bromine-radical-mediated C−H activation strategy can be also applied to the enantioselective coupling of alkylarenes with chloroformate for the synthesis of chiral α-aryl esters.


Author(s):  
David W. C. MacMillan ◽  
Yufan Liang ◽  
Xiaheng Zhang

<p>Over the last three decades, significant progress has been made in the development of methods to construct <i>sp<sup>2</sup></i> C–N bonds using palladium, copper, or nickel catalysis. However, the incorporation of alkyl substrates to form <i>sp<sup>3</sup></i> C–N bonds remains one of the major challenges in the field of cross-coupling chemistry. Here, we demonstrate that the synergistic combination of copper catalysis and photoredox catalysis can provide a general platform to address this long-standing challenge. This novel cross-coupling system employs naturally abundant alkyl carboxylic acids and commercially available <i>N</i>-nucleophiles as coupling partners, and is applicable to a wide variety of primary, secondary, and tertiary alkyl carboxylic acids (via in situ iodonium activation). At the same time, a vast array of <i>N</i>-nucleophiles, including <i>N</i>-heterocycles, amides, sulfonamides, and anilines, can undergo C–N coupling to provide <i>N</i>-alkyl products in good to excellent efficiency at room temperature and in short order (5 minutes to 1 hour). We have also demonstrated that this C–N coupling protocol can be applied to substrates bearing multiple amines with high regioselectivity, as well as complex drug molecules, enabling the rapid construction of molecular complexity and the late stage functionalization of bioactive pharmaceuticals.</p>


Author(s):  
David W. C. MacMillan ◽  
Yufan Liang ◽  
Xiaheng Zhang

<p>Over the last three decades, significant progress has been made in the development of methods to construct <i>sp<sup>2</sup></i> C–N bonds using palladium, copper, or nickel catalysis. However, the incorporation of alkyl substrates to form <i>sp<sup>3</sup></i> C–N bonds remains one of the major challenges in the field of cross-coupling chemistry. Here, we demonstrate that the synergistic combination of copper catalysis and photoredox catalysis can provide a general platform to address this long-standing challenge. This novel cross-coupling system employs naturally abundant alkyl carboxylic acids and commercially available <i>N</i>-nucleophiles as coupling partners, and is applicable to a wide variety of primary, secondary, and tertiary alkyl carboxylic acids (via in situ iodonium activation). At the same time, a vast array of <i>N</i>-nucleophiles, including <i>N</i>-heterocycles, amides, sulfonamides, and anilines, can undergo C–N coupling to provide <i>N</i>-alkyl products in good to excellent efficiency at room temperature and in short order (5 minutes to 1 hour). We have also demonstrated that this C–N coupling protocol can be applied to substrates bearing multiple amines with high regioselectivity, as well as complex drug molecules, enabling the rapid construction of molecular complexity and the late stage functionalization of bioactive pharmaceuticals.</p>


2018 ◽  
Author(s):  
Erin Stache ◽  
Alyssa B. Ertel ◽  
Tomislav Rovis ◽  
Abigail G. Doyle

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.


2021 ◽  
Vol 143 (5) ◽  
pp. 2200-2206
Author(s):  
Duanyang Kong ◽  
Maxime Munch ◽  
Qiqige Qiqige ◽  
Christopher J. C. Cooze ◽  
Benjamin H. Rotstein ◽  
...  

ChemInform ◽  
2014 ◽  
Vol 45 (41) ◽  
pp. no-no
Author(s):  
Deqiang Liang ◽  
Mang Wang ◽  
Ying Dong ◽  
Yaru Guo ◽  
Qun Liu

Author(s):  
Darya O. Prima ◽  
Malena Madiyeva ◽  
Julia V. Burykina ◽  
Mikhail E. Minyaev ◽  
Daniil A. Boiko ◽  
...  

The mechanism of the C–N cross-coupling reaction, catalyzed by Pd/NHC, was evaluated at the molecular and nanoscale levels. The first evidence for the involvement of a “cocktail”-type system in the Buchwald–Hartwig reaction is provided.


Sign in / Sign up

Export Citation Format

Share Document