Efficient Pd-Catalyzed Hydrodehalogenation of o-Haloanilides in Water

Synlett ◽  
2020 ◽  
Vol 31 (11) ◽  
pp. 1121-1125
Author(s):  
Zewei Mao ◽  
Yanling Tang ◽  
Minxin Li ◽  
Hui Gao ◽  
Gaoxiong Rao

In the present work, we have developed a practical methodology for the hydrodehalogenation of o-haloanilides using PdCl2 at 100 °C under mild conditions in water. The catalytic system could selectively dehalogenate both aryl chloride and aryl bromide and exhibit a broad functional group tolerance.

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1232-1238
Author(s):  
Guofu Zhang ◽  
Yunzhe Xing ◽  
Shengjun Xu ◽  
Chengrong Ding ◽  
Shang Shan

An efficient Fe(III), l-valine, and 4-OH-TEMPO catalytic system was found for the oxidation of alcohols followed by condensation with sulfinamide or sulfonamide in one pot for the synthesis of N-sulfinyl- and N-sulfonylimines compounds under mild conditions. This transformation accommodates a variety of substrates, shows high functional-group tolerance, and affords the corresponding products in good to excellent yields.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guo-Quan Sun ◽  
Wei Zhang ◽  
Li-Li Liao ◽  
Li Li ◽  
Zi-Hao Nie ◽  
...  

AbstractElectrochemical catalytic reductive cross couplings are powerful and sustainable methods to construct C−C bonds by using electron as the clean reductant. However, activated substrates are used in most cases. Herein, we report a general and practical electro-reductive Ni-catalytic system, realizing the electrocatalytic carboxylation of unactivated aryl chlorides and alkyl bromides with CO2. A variety of unactivated aryl bromides, iodides and sulfonates can also undergo such a reaction smoothly. Notably, we also realize the catalytic electrochemical carboxylation of aryl (pseudo)halides with CO2 avoiding the use of sacrificial electrodes. Moreover, this sustainable and economic strategy with electron as the clean reductant features mild conditions, inexpensive catalyst, safe and cheap electrodes, good functional group tolerance and broad substrate scope. Mechanistic investigations indicate that the reaction might proceed via oxidative addition of aryl halides to Ni(0) complex, the reduction of aryl-Ni(II) adduct to the Ni(I) species and following carboxylation with CO2.


CCS Chemistry ◽  
2019 ◽  
pp. 106-116 ◽  
Author(s):  
Lin Huang ◽  
Yue Cai ◽  
Hui-Jun Zhang ◽  
Chao Zheng ◽  
Li-Xin Dai ◽  
...  

Asymmetric construction of quinuclidine derivatives has been realized by an iridium-catalyzed allylic dearomatization reaction. The catalytic system, derived from [Ir(cod)Cl] 2 and the Feringa ligand, tolerates a broad range of substrates. A large array of quinuclidine derivatives can be obtained under mild conditions in good to excellent yields (68%–96%), diastereoselectivity (up to >20/1 dr), and enantioselectivity (up to >99% ee). These products feature versatile functional group diversity and can undergo diverse transformations. A model that accounts for the origin of the stereoselectivity has been proposed based on density functional theory (DFT) calculations.


Synthesis ◽  
2019 ◽  
Vol 51 (17) ◽  
pp. 3221-3230 ◽  
Author(s):  
Wei Sun ◽  
Mingjuan Zhang ◽  
Peilang Li ◽  
Yiqun Li

A novel and highly efficient one-pot synthesis of polysubstituted imidazoles from α-hydroxyphenylacetic acids, diphenylacetylene, and amines has been achieved by Pd(OAc)2/Ce(SO4)2/Bi(NO3)3 trimetallic catalytic system. A series of control experiments showed that this overall reaction occurs through a one-pot cascade process combining the steps of decarboxylation of α-hydroxyphenylacetic acids, Wacker-type oxidation of diphenylacetylene, and Debus–Radziszewski annulation of aryl aldehydes and benzil generated in situ, as well as amines. This reaction represents a novel multicomponent reaction using α-hydroxyphenylacetic acids and diphenylacetylene as sources of aryl aldehydes and a β-diketone. This process exhibits a broad substrate scope and a good functional group tolerance to assemble the corresponding polysubstituted imidazoles in excellent yields (72–88%) under mild conditions.


2019 ◽  
Author(s):  
Hang Shi ◽  
Lu Yi ◽  
Jiang Weng ◽  
Katherine Bay ◽  
Xiangyang Chen ◽  
...  

<p>Site-selective functionalizations of C–H bonds will ultimately afford chemists transformative tools for editing and constructing complex molecular architectures<sup>1-4</sup>. Towards this goal, developing strategies to activate C–H bonds that are distal from a functional group is essential<sup>4-6</sup>. In this context, distinguishing remote C–H bonds on adjacent carbon atoms is an extraordinary challenge due to the lack of electronic or steric bias between the two positions. Herein, we report the design of a catalytic system leveraging a remote directing template and a transient norbornene mediator to selectively activate a previously inaccessible remote C–H bond that is one bond further away. The generality of this approach has been demonstrated with a range of heterocycles, including a complex anti-leukemia agent, and hydrocinnamic acid substrates.</p>


2019 ◽  
Author(s):  
John Montgomery ◽  
Alexander W. Rand

A new method to access alpha-arylated benzamides has been enabled by metallaphotoredox catalysis. This system allows for non-directed C–H functionalization of N-alkyl benzamides using a dual nickel/iridium catalytic system to form tertiary stereocenters in good enantiomeric excess and moderate yields. This reaction shows excellent functional group compatibility and can be performed using a number of sterically and electronically different aryl bromides and secondary benzamides.


2019 ◽  
Author(s):  
John Montgomery ◽  
Alexander W. Rand

A new method to access alpha-arylated benzamides has been enabled by metallaphotoredox catalysis. This system allows for non-directed C–H functionalization of N-alkyl benzamides using a dual nickel/iridium catalytic system to form tertiary stereocenters in good enantiomeric excess and moderate yields. This reaction shows excellent functional group compatibility and can be performed using a number of sterically and electronically different aryl bromides and secondary benzamides.


Author(s):  
Shuangshuang Li ◽  
Ju Qiu ◽  
Bowen Li ◽  
Zuolian Sun ◽  
Peizhong Xie ◽  
...  

A practical palladium/calcium catalytic system was developed for dehydrative allylation concerning unactivated allylic alcohols. EtOH solvent with H2O additive was identified as powerful media to accelerate proton transfer. That catalytic...


Synlett ◽  
2021 ◽  
Author(s):  
Xianqing Wu ◽  
Mohini Shrestha ◽  
Yifeng Chen

AbstractChiral-auxiliary-mediated synthesis represents the most frequently used synthetic tool for the induction of chirality on α-position of γ-lactams in organic synthesis. However, the general strategy requires the stoichiometric use of chiral reagents with multiple manipulation steps. Transition-metal-catalyzed asymmetric alkene dicarbofunctionalization using readily available substrates under mild conditions allows the simultaneous construction of two vicinal chemical bonds and a chiral carbon center, hence, gain expedient access to chiral heterocycles. Herein, we disclose a Ni-catalyzed enantioselective reaction of 3-butenyl carbamoyl chloride and primary alkyl iodide enabled by a newly designed chiral 8-quinoline imidazoline ligand (8-Quinim). This protocol features broad functional group tolerance and high enantioselectivities, achieving unprecedented synthesis of chiral nonaromatic heterocycles via catalytic reductive protocol.1 Introduction2 Development of 8-Quinim Ligand3 Nickel/8-Quinim-Catalyzed Enantioselective Synthesis of Chiral α-Alkylated γ-Lactam4 Conclusion and Outlook


2021 ◽  
Vol 19 (35) ◽  
pp. 7701-7705
Author(s):  
Chuanliu Yin ◽  
Tianshuo Zhong ◽  
Xiangyun Zheng ◽  
Lianghao Li ◽  
Jian Zhou ◽  
...  

An Rh(iii)-catalyzed annulation of phthalazinones and various allenes was developed, leading to the formation of indazole derivatives. This catalytic system exhibits excellent functional group tolerance and atom economy.


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