scholarly journals Photo-induced catalytic halopyridylation of alkenes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shi-Yu Guo ◽  
Fan Yang ◽  
Ting-Ting Song ◽  
Yu-Qing Guan ◽  
Xiang-Ting Min ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Heck Reaction ◽  
Cross Coupling ◽  
Photoredox Catalysis ◽  
Radical Process ◽  
Type Reaction ◽  
Plausible Mechanism ◽  
Mechanistic Investigations ◽  
Neutral Conditions

AbstractThe Mizoroki-Heck reaction and its reductive analogue are staples of organic synthesis, but the ensuing products often lack a chemical handle for further transformation. Here we report an atom-economical cross-coupling of halopyridines and unactivated alkenes under photoredox catalysis to afford a series of alkene halopyridylation products. This protocol with mild and redox neutral conditions contributes broad substrate scope. As a complement to conventional Heck-type reaction, this radical process avoids the involvement of β-H elimination and thus useful pyridyl and halide groups could be simultaneously and regioselectively incorporated onto alkenes. The success depends on TFA-promoted domino photocatalytic oxidative quenching activation and radical-polar crossover pathway. Plausible mechanism is proposed based on mechanistic investigations. Moreover, the reserved C − X bonds of these products are beneficial for performing further synthetic elaborations.

scholarly journals Asymmetric benzylic C(sp3)−H acylation via dual nickel and photoredox catalysis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Leitao Huan ◽  
Xiaomin Shu ◽  
Weisai Zu ◽  
De Zhong ◽  
Haohua Huo
Keyword(s):  
Carboxylic Acids ◽  
Organic Synthesis ◽  
Late Stage ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Photoredox Catalysis ◽  
Mechanistic Studies ◽  
Cross Coupling Reaction ◽  
Aryl Ketones ◽  
Alkyl Benzenes

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.

Ni(0)-Catalyzed α-Allylic Alkylation of Regular Ketones with 1,3-Dienes under pH and Redox-neutral Conditions

2019 ◽  
Author(s):  
Tiantian Chen ◽  
Yang Yang ◽  
Liyu Xie ◽  
Haijian Yang ◽  
Guangbin Dong ◽  
...  
Keyword(s):  
Oxidative Addition ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Dual Role ◽  
Allylic Alkylation ◽  
Cross Coupling Reaction ◽  
Neutral Conditions

<p>We report a Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A variety of a-allylic alkylation products were formed in an 1,2-addition manner with excellent regioselectivity. Water was found to significantly accelerate this transformation. A HO-Ni-H species generated from oxidative addition of Ni(0) to H<sub>2</sub>O is proposed to play a “dual role” in activating both the ketone and the diene substrate.</p>

Microwave Assisted Organic Synthesis: Cross Coupling and Multicomponent Reactions

2013 ◽  
Vol 17 (5) ◽  
pp. 474-490 ◽  
Author(s):  
Amit Kumar Gupta ◽  
Neetu Singh ◽  
Krishna Nand Singh
Keyword(s):  
Organic Synthesis ◽  
Multicomponent Reactions ◽  
Cross Coupling ◽  
Microwave Assisted

Recent Developments in Heck-Type Reaction of Unactivated Alkenes and Alkyl Electrophiles

Synthesis ◽  
2020 ◽  
Author(s):  
Lili Shi ◽  
Junkai Fu ◽  
Shuangqiu Gao ◽  
Le Chang ◽  
Binglin Wang
Keyword(s):  
Heck Reaction ◽  
Alkyl Radicals ◽  
Type Reaction ◽  
The Past ◽  
Alkyl Electrophiles ◽  
Recent Developments ◽  
Palladium Catalyzed ◽  
Initial Work ◽  
Activated Olefins ◽  
Pseudo Halides

AbstractThe Mizoroki–Heck reaction is considered as one of the most ingenious and widely used methods for constructing C–C bonds. This reaction mainly focuses on activated olefins (styrenes, acrylates, or vinyl ethers) and aryl/vinyl (pseudo) halides. In comparison, the studies on unactivated alkenes and alkyl electrophiles are far less due to the low reactivity, poor selectivity, as well as competitive β-H elimination. In the past years, a growing interest has thus been devoted and significant breakthroughs have been achieved in the employment of unactivated alkenes and alkyl electrophiles as the reaction components, and this type of coupling is called as Heck-type or Heck-like reaction, which distinguishes from the traditional Heck reaction. Herein, we give a brief summary on Heck-type reaction between unactivated alkenes and alkyl electrophlies, covering its initial work, recent advancements, and mechanistic discussions.1 Introduction2 Intramolecular Heck-Type Reaction of Unactivated Alkenes and Alkyl Electrophiles2.1 Cobalt-Catalyzed Intramolecular Heck-Type Reaction2.2 Palladium-Catalyzed Intramolecular Heck-Type Reaction2.3 Nickel-Catalyzed Intramolecular Heck-Type Reaction2.4 Photocatalysis and Multimetallic Protocol for Intramolecular Heck-Type Reaction3 Intermolecular Heck-Type Reaction of Unactivated Alkenes and Alkyl Electrophiles3.1 Electrophilic Trifluoromethylating Reagent as Reaction Partners3.2 Alkyl Electrophiles as Reaction Partners4 Oxidative Heck-Type Reaction of Unactivated Alkenes and Alkyl Radicals5 Conclusions and Outlook

Recent Advances in C–Br Bond Formation

Synlett ◽  
2021 ◽  
Author(s):  
Ying-Yeung Yeung ◽  
Jonathan Wong
Keyword(s):  
Organic Synthesis ◽  
Aromatic Compounds ◽  
Bond Formation ◽  
Cross Coupling ◽  
Catalytic Site ◽  
Atom Transfer ◽  
Bond Forming ◽  
Recent Advances ◽  
Catalytic Asymmetric ◽  
Site Selective

AbstractOrganobromine compounds are extremely useful in organic synthesis. In this perspective, a focused discussion on some recent advancements in C–Br bond-forming reactions is presented.1 Introduction2 Selected Recent Advances2.1 Catalytic Asymmetric Bromopolycyclization of Olefinic Substrates2.2 Catalytic Asymmetric Intermolecular Bromination2.3 Some New Catalysts and Reagents for Bromination2.4 Catalytic Site-Selective Bromination of Aromatic Compounds2.5 sp3 C–H Bromination via Atom Transfer/Cross-Coupling3 Outlook

Cross-Coupling of Organic Halides with Alkenes: The Heck Reaction

ChemInform ◽  
2005 ◽  
Vol 36 (8) ◽  
Author(s):  
Stefan Braese ◽  
Armin de Meijere
Keyword(s):  
Heck Reaction ◽  
Cross Coupling ◽  
Organic Halides

Desulfonylation via Radical Process: Recent Developments in Organic Synthesis

2021 ◽  
Author(s):  
Xue-Qiang Chu ◽  
Danhua Ge ◽  
Yan-Ying Cui ◽  
Zhi-Liang Shen ◽  
Chao-Jun Li
Keyword(s):  
Organic Synthesis ◽  
Radical Process ◽  
Recent Developments

Palladium Nanocatalysts for Cascade C−N Cross‐Coupling/Heck Reaction

2021 ◽  
Vol 10 (4) ◽  
pp. 872-878
Author(s):  
Ivan Rodriguez‐Oliva ◽  
Noelia Losada‐Garcia ◽  
A. Sofia Santos ◽  
M. Manuel B. Marques ◽  
Jose M. Palomo
Keyword(s):  
Heck Reaction ◽  
Cross Coupling ◽  
Palladium Nanocatalysts

UV-Light-Induced Dehydrogenative N-Acylation of Amines with 2-Nitrobenzaldehydes to Give 2-Aminobenzamides

Synthesis ◽  
2022 ◽  
Author(s):  
Dishu Zeng ◽  
Tianbao Yang ◽  
Niu Tang ◽  
Wei Deng ◽  
Jiannan Xiang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Organic Synthesis ◽  
Efficient Method ◽  
Building Block ◽  
Room Temperature ◽  
Uv Light ◽  
Amino Acid Derivatives ◽  
One Pot ◽  
Plausible Mechanism ◽  
High Yields

A simple, mild, green and efficient method for the synthesis of 2-aminobenzamides was highly desired in organic synthesis. Herein, we developed an efficient, one-pot strategy for the synthesis of 2-aminobenzamides with high yields irradiated by UV light. 32 examples proceeded successfully by this photo-induced protocol. The yield reached up to 92%. The gram scale was also achieved easily. This building block could be applied in the preparation of quinazolinones derivatives. Amino acid derivatives could be employed smoothly at room temperature. Finally, a plausible mechanism was proposed.

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