Differentiation and Functionalization of Adjacent, Remote C–H Bonds

2019 ◽  
Author(s):  
Hang Shi ◽  
Lu Yi ◽  
Jiang Weng ◽  
Katherine Bay ◽  
Xiangyang Chen ◽  
...  
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Hydrocinnamic Acid ◽  
Molecular Architectures ◽  
Site Selective ◽  
Developing Strategies

<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>

Differentiation and Functionalization of Adjacent, Remote C–H Bonds

2019 ◽  
Author(s):  
Hang Shi ◽  
Lu Yi ◽  
Jiang Weng ◽  
Katherine Bay ◽  
Xiangyang Chen ◽  
...  
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Hydrocinnamic Acid ◽  
Molecular Architectures ◽  
Site Selective ◽  
Developing Strategies

<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>

Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

2020 ◽  
Author(s):  
Chang-Sheng Wang ◽  
Sabrina Monaco ◽  
Anh Ngoc Thai ◽  
Md. Shafiqur Rahman ◽  
Chen Wang ◽  
...  
Keyword(s):  
Catalytic System ◽  
Lewis Acid ◽  
Hydrogen Transfer ◽  
Acid Catalysis ◽  
Rate Limiting Step ◽  
Site Selectivity ◽  
Set Up ◽  
Site Selective ◽  
First Time ◽  
Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

Enantioselective alpha-Arylation of Benzamides via Synergistic Nickel and Metallaphotoredox Catalysis

2019 ◽  
Author(s):  
John Montgomery ◽  
Alexander W. Rand
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Enantiomeric Excess ◽  
New Method ◽  
Aryl Bromides

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.

Enantioselective alpha-Arylation of Benzamides via Synergistic Nickel and Metallaphotoredox Catalysis

2019 ◽  
Author(s):  
John Montgomery ◽  
Alexander W. Rand
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Enantiomeric Excess ◽  
New Method ◽  
Aryl Bromides

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.

Direct synthesis of indazole derivatives via Rh(iii)-catalyzed C–H activation of phthalazinones and allenes

2021 ◽  
Vol 19 (35) ◽  
pp. 7701-7705
Author(s):  
Chuanliu Yin ◽  
Tianshuo Zhong ◽  
Xiangyun Zheng ◽  
Lianghao Li ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Direct Synthesis ◽  
Atom Economy

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.

scholarly journals Gold(I)-catalyzed synthesis of γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with alcohols

2011 ◽  
Vol 7 ◽  
pp. 1198-1204 ◽  
Author(s):  
Michel Chiarucci ◽  
Mirko Locritani ◽  
Gianpiero Cera ◽  
Marco Bandini
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Direct Synthesis ◽  
Catalytic Process ◽  
Primary Alcohols

Gold(I)-N-heterocyclic carbene (NHC) complexes proved to be a reliable catalytic system for the direct synthesis of functionalized γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with primary alcohols. Good isolated chemical yields were obtained for a range of malonyl and acetate derivatives. The good performance in reagent-grade solvents and the functional group/moisture tolerance make this catalytic process a promising route for the synthesis of architecturally complex polycyclic structures.

scholarly journals A general method for site-selective Csp3–S bond formation via cooperative catalysis

2020 ◽  
Vol 11 (5) ◽  
pp. 1276-1282 ◽  
Author(s):  
Yuman Qin ◽  
Yujie Han ◽  
Yongzhen Tang ◽  
Junfa Wei ◽  
Mingyu Yang
Keyword(s):  
Functional Group ◽  
Bond Formation ◽  
Aliphatic Amines ◽  
Cooperative Catalysis ◽  
Site Selective ◽  
General Method

A copper-catalyzed site-selective thiolation of Csp3–H bonds of aliphatic amines was developed. The method features a broad substrate scope and good functional group tolerance.

scholarly journals Copper-Catalyzed Amination of Vinyl Azides to α-Ketoamides

SynOpen ◽  
2019 ◽  
Vol 03 (04) ◽  
pp. 91-95
Author(s):  
Yu Wang ◽  
Dongling Zhang ◽  
Kaining Zhang ◽  
Zhenhua Liu ◽  
Jing Lin ◽  
...  
Keyword(s):  
Benzoic Acid ◽  
Catalytic System ◽  
Functional Group ◽  
Efficient Approach ◽  
Broad Scope ◽  
Vinyl Azides ◽  
Oxidative Generation

An efficient approach for the amination of vinyl azides with N,N-dialkylacylamides has been developed. By using this protocol, structurally important α-ketoamides can be easily synthesized. The key to success is not only the introduction of a Cu(I)/oxygen catalytic system but also the utilization of t-BuOCl and benzoic acid as additives. The reaction is operationally simple, scalable, and displays broad scope and functional group tolerance. A possible mechanism involving copper-catalyzed oxidative generation of peroxide radicals is proposed.

Palladium-catalyzed site-selective arylation of aliphatic ketones enabled by a transient ligand

2018 ◽  
Vol 54 (22) ◽  
pp. 2759-2762 ◽  
Author(s):  
Lei Pan ◽  
Ke Yang ◽  
Guigen Li ◽  
Haibo Ge
Keyword(s):  
Functional Group ◽  
Direct Arylation ◽  
Aliphatic Ketones ◽  
Site Selectivity ◽  
Palladium Catalyzed ◽  
High Site ◽  
Site Selective

A direct arylation of C–H bonds of ketones enabled by a cheap and commercially available transient ligand with high site-selectivity and functional group compatibility is reported.

scholarly journals Sodium Copper Chlorophyllin Catalyzed Chemoselective Oxidation of Benzylic Alcohols and Diarylmethanes in Water

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1883 ◽  
Author(s):  
Shi-juan Liu ◽  
Miao Zhang ◽  
Rong Lu ◽  
Xiu-ying Li ◽  
Guang-bo Che
Keyword(s):  
Catalytic System ◽  
Functional Group ◽  
Secondary Alcohols ◽  
Benzylic Alcohols ◽  
Highly Efficient ◽  
Aryl Ketones ◽  
Sodium Copper Chlorophyllin

We report the highly efficient and chemoselective oxidation of benzylic alcohols catalyzed by sodium copper chlorophyllin in water, producing corresponding arylcarbonyl compounds. Importantly, the catalytic system exhibits a wide substrate scope and high functional group tolerance. Moreover, secondary alcohols and even diarylmethanes were smoothly oxidized to the desired aryl ketones with excellent yields.

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