scholarly journals Versatile cross-dehydrogenative coupling of heteroaromatics and hydrogen donors via decatungstate photocatalysis

2017 ◽  
Vol 53 (15) ◽  
pp. 2335-2338 ◽  
Author(s):  
Matteo C. Quattrini ◽  
Saki Fujii ◽  
Keiichi Yamada ◽  
Takahide Fukuyama ◽  
Davide Ravelli ◽  
...  
Keyword(s):  
Dehydrogenative Coupling ◽  
Hydrogen Donors

A facile sunlight-induced derivatization of heteroaromaticsviaTBADT photocatalyzed C–H functionalization in amides, ethers, alkanes and aldehydes is described.

scholarly journals Photoelectrocatalytic Cross-Dehydrogenative Coupling of Unactivated Aliphatic Hydrogen Donors with Benzothiazoles: Synthetic Applications and Mechanistic Insights

2020 ◽  
Author(s):  
Luca Capaldo ◽  
Lorenzo L. Quadri ◽  
Daniele Merli ◽  
Davide Ravelli
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Hydrogen Atom Transfer ◽  
Faradaic Efficiency ◽  
Radical Intermediates ◽  
Potentiostatic Mode ◽  
Dehydrogenative Coupling ◽  
Hydrogen Donors ◽  
Very High

We report herein a photoelectrocatalytic strategy for the smooth preparation of 2-alkylbenzothiazoles via the cross-dehydrogenative coupling of unactivated aliphatic hydrogen donors (e.g. alkanes) with benzothiazoles. We used tetrabutylammonium decatungstate (TBADT) as the photocatalyst to cleave the strong C(sp3)-H bonds embedded in the chosen substrates via Hydrogen Atom Transfer (HAT), while electrochemistry ensured the success of this net-oxidative transformation by scavenging the extra electrons. The reaction progress was monitored through kinetic analysis, highlighting the transient formation of the redox-neutral adduct 2-alkylbenzothiazoline. Further cyclic voltammetry and laser flash photolysis experiments unveiled the chameleonic behavior of TBADT that features a three-fold role: HAT photocatalyst to activate alkanes, photoredox catalyst to activate the 2-alkylbenzothiazoline and electrocatalyst to promote the oxidation of short-lived radical intermediates. The adopted potentiostatic mode allowed to tame the multi-faceted reactivity of TBADT and to ensure its recovery after each catalytic cycle with a very high faradaic efficiency. We proved the versatility of the proposed approach by replacing the potentiostat with a couple of cheap batteries in the preparation of the desired products.<br>

scholarly journals Photoelectrocatalytic Cross-Dehydrogenative Coupling of Unactivated Aliphatic Hydrogen Donors with Benzothiazoles: Synthetic Applications and Mechanistic Insights

2020 ◽  
Author(s):  
Luca Capaldo ◽  
Lorenzo L. Quadri ◽  
Daniele Merli ◽  
Davide Ravelli
Keyword(s):  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Laser Flash ◽  
Hydrogen Atom Transfer ◽  
Faradaic Efficiency ◽  
Radical Intermediates ◽  
Potentiostatic Mode ◽  
Dehydrogenative Coupling ◽  
Hydrogen Donors ◽  
Very High

We report herein a photoelectrocatalytic strategy for the smooth preparation of 2-alkylbenzothiazoles via the cross-dehydrogenative coupling of unactivated aliphatic hydrogen donors (e.g. alkanes) with benzothiazoles. We used tetrabutylammonium decatungstate (TBADT) as the photocatalyst to cleave the strong C(sp3)-H bonds embedded in the chosen substrates via Hydrogen Atom Transfer (HAT), while electrochemistry ensured the success of this net-oxidative transformation by scavenging the extra electrons. The reaction progress was monitored through kinetic analysis, highlighting the transient formation of the redox-neutral adduct 2-alkylbenzothiazoline. Further cyclic voltammetry and laser flash photolysis experiments unveiled the chameleonic behavior of TBADT that features a three-fold role: HAT photocatalyst to activate alkanes, photoredox catalyst to activate the 2-alkylbenzothiazoline and electrocatalyst to promote the oxidation of short-lived radical intermediates. The adopted potentiostatic mode allowed to tame the multi-faceted reactivity of TBADT and to ensure its recovery after each catalytic cycle with a very high faradaic efficiency. We proved the versatility of the proposed approach by replacing the potentiostat with a couple of cheap batteries in the preparation of the desired products.<br>

Photoelectrochemical cross-dehydrogenative coupling of benzothiazoles with strong aliphatic C–H bonds

2021 ◽  
Author(s):  
Luca Capaldo ◽  
Lorenzo L. Quadri ◽  
Daniele Merli ◽  
Davide Ravelli
Keyword(s):  
Dehydrogenative Coupling ◽  
Hydrogen Donors ◽  
Oxidative Alkylation

The merging of decatungstate photocatalysis with electrochemistry enabled the net-oxidative alkylation of benzothiazoles with aliphatic hydrogen donors featuring strong C(sp3)–H bonds.

Thermally-Induced Dehydrogenative Coupling of Organosilanes and H-Terminated Silicon Quantum Dots onto Germanane Surfaces

2020 ◽  
Author(s):  
Haoyang Yu ◽  
Alyxandra Thiessen ◽  
Md Asjad Hossain ◽  
Marc Julian Kloberg ◽  
Bernhard Rieger ◽  
...  
Keyword(s):  
2D Materials ◽  
Future Generation ◽  
Optical Devices ◽  
Surface Reactivity ◽  
Organic Monolayers ◽  
Present Contribution ◽  
Thermally Induced ◽  
Dehydrogenative Coupling ◽  
Silicon Quantum Dot ◽  
Covalently Bonded

<div><div><div><p>Covalently bonded organic monolayers play important roles in defining the solution processability, ambient stability, and electronic properties of two-dimensional (2D) materials such as Ge nanosheets (GeNSs); they also hold promise of providing avenues for the fabrication of future generation electronic and optical devices. Functionalization of GeNS normally involves surface moieties linked through covalent Ge−C bonds. In the present contribution we extend the scope of surface linkages to include Si−Ge bonding and present the first demonstration of heteronuclear dehydrocoupling of organosilanes to hydride-terminated GeNSs obtained from the deintercalation and exfoliation of CaGe2. We further exploit this new surface reactivity and demonstrated the preparation of directly bonded silicon quantum dot-Ge nanosheet hybrids.</p></div></div></div>

Transition-Metal-Free Synthetic Strategies for the Cross-Coupling Reactions in Water: A Green Approach

2020 ◽  
Vol 07 ◽  
Author(s):  
Tanmay Chatterjee ◽  
Nilanjana Mukherjee
Keyword(s):  
Transition Metal ◽  
Organic Solvents ◽  
Aqueous Media ◽  
Cross Coupling ◽  
Transition Metal Catalysts ◽  
Synthetic Methods ◽  
Coupling Reactions ◽  
Organic Transformations ◽  
Green Approach ◽  
Dehydrogenative Coupling

Abstract: A natural driving force is always working behind the synthetic organic chemists towards the development of ‘green’ synthetic methodologies for the synthesis of useful classes of organic molecules having potential applications. The majority of the essential classes of organic transformations, including C-C and C-X (X = heteroatom) bond-forming crosscoupling reactions, cross dehydrogenative-coupling (CDC) mostly rely on the requirement of transition-metal catalysts and hazardous organic solvents. Hence, the scope in developing green synthetic strategies by avoiding the use of transitionmetal catalysts and hazardous organic solvents for those important and useful classes of organic transformations is very high. Hence, several attempts are made so far. Water being the most abundant, cheap, and green solvent in the world; numerous synthetic methods have been developed in an aqueous medium. In this review, the development of transitionmetal- free green synthetic strategies for various important classes of organic transformations such as C-C and C-X bondforming cross-coupling, cross dehydrogenative-coupling, and oxidative-coupling in an aqueous media is discussed.

Ruthenium-catalyzed synthesis of N-substituted lactams by acceptorless dehydrogenative coupling of diols with primary amines

2019 ◽  
Vol 55 (82) ◽  
pp. 12384-12387 ◽  
Author(s):  
Yanling Zheng ◽  
Xufeng Nie ◽  
Yang Long ◽  
Li Ji ◽  
Haiyan Fu ◽  
...  
Keyword(s):  
Phosphine Ligand ◽  
Primary Amines ◽  
Dehydrogenative Coupling ◽  
One Step

The first synthesis of N-substituted lactams via an acceptorless dehydrogenative coupling of diols with primary amines in one step was enabled by combining Ru3(CO)12 with a hybrid N-heterocyclic carbene–phosphine–phosphine ligand as the catalyst.

On-Surface Synthesis of Chiral π-Conjugate Porphyrin Tapes by Substrate-Regulated Dehydrogenative Coupling

2019 ◽  
Vol 123 (37) ◽  
pp. 23007-23013 ◽  
Author(s):  
Feifei Xiang ◽  
Yan Lu ◽  
Zhongping Wang ◽  
Huanxin Ju ◽  
Gianluca Di Filippo ◽  
...  
Keyword(s):  
Dehydrogenative Coupling

scholarly journals A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Huang ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Evolution ◽  
Alkyl Radical ◽  
Cobalt Catalyst ◽  
Alkylation Reaction ◽  
Hydrogen Atom Abstraction ◽  
Dehydrogenative Coupling ◽  
Radical Generation ◽  
Limited Scope

AbstractHydrogen atom abstraction (HAT) from C(sp3)–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report a photo-induced and chemical oxidant-free cross-dehydrogenative coupling (CDC) between alkanes and heteroarenes using catalytic chloride and cobalt catalyst. Couplings of strong C(sp3)–H bond-containing substrates and complex heteroarenes, have been achieved with satisfactory yields. This dual catalytic platform features the in situ engendered chlorine radical for alkyl radical generation and exploits the cobaloxime catalyst to enable the hydrogen evolution for catalytic turnover. The practical value of this protocol was demonstrated by the gram-scale synthesis of alkylated heteroarene with merely 3 equiv. alkane loading.

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