Iodine(III) promotes cross-dehydrogenative coupling of N-hydroxyphthalimide and unactivated C(sp3)–H bonds

AbstractCross-dehydrogenative coupling reactions provide a method to construct new chemical bonds by direct C–H activation without any pre-functionalization. Compared to functionalization of a C–H bond α- to ether oxygen, α- to carbonyl, or at a benzylic position, functionalization of unactivated hydrocarbons is difficult and often requires high temperatures, a transition-metal catalyst, or a superstoichiometric quantity of volatile, toxic, and explosive tert-butylhydroperoxide. Here, a cross-dehydrogenative C–O coupling reaction of N-hydroxyphthalimide with unactivated alkanes, nitriles, ethers, and thioethers has been realized by using iodobenzene diacetate as the radical initiator. The current protocol enables efficient functionalization of unactivated hydrocarbons and nitriles through inert C(sp3)–H bond activation under mild reaction conditions. O-substituted NHPI derivatives are generated in good yields under metal-free conditions.

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(Diacetoxyiodo)benzene-Mediated Transition-Metal-Free Amination of C(sp3)–H Bonds Adjacent to Heteroatoms with Azoles: Synthesis of N-Alkylated Azoles

Synlett ◽

10.1055/s-0037-1610293 ◽

2018 ◽

Vol 29 (18) ◽

pp. 2432-2436 ◽

Cited By ~ 17

Author(s):

Can Jin ◽

Weike Su ◽

Bin Sun ◽

Zhiyang Yan

Keyword(s):

Free Radical ◽

Transition Metal ◽

Coupling Reaction ◽

Metal Catalyst ◽

Metal Free ◽

Alternative Method ◽

Dehydrogenative Coupling ◽

Wide Range ◽

Ready Access

A novel PhI(OAc)2-mediated cross-dehydrogenative coupling reaction of α-C(sp3)–H bonds adjacent to a hetero atom with various azoles has been developed, which provides an alternative method for constructing C–N bonds with high atom efficiency. This new protocol requires no metal catalyst and it provides ready access to a wide range of N-alkylated azole derivatives in moderate to excellent yields by using commercially available PhI(OAc)2 as the sole oxidant. Furthermore, the method is effective on a gram scale, which highlights the practicality of this transformation. The result of radical-captured experiments indicated that the transformation might involve a free-radical pathway.

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Potassium carbonate-mediated tandem C–S and C–N coupling reaction for the synthesis of phenothiazines under transition-metal-free and ligand-free conditions

RSC Advances ◽

10.1039/c6ra01295g ◽

2016 ◽

Vol 6 (29) ◽

pp. 24257-24260 ◽

Cited By ~ 4

Author(s):

San Wu ◽

Wei-Ye Hu ◽

Song-Lin Zhang

Keyword(s):

Transition Metal ◽

Potassium Carbonate ◽

Coupling Reaction ◽

Metal Catalyst ◽

Phenothiazine Derivatives ◽

Transition Metal Catalyst ◽

Metal Free ◽

Efficient Approach ◽

Ligand Free

A potassium carbonate-mediated tandem coupling reaction for the synthesis of phenothiazines is described. This protocol affords an efficient approach for the construction of phenothiazine derivatives without the need for addition of transition-metal catalyst or ligand.

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An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

Current Organic Synthesis ◽

10.2174/1570179415666180622102458 ◽

2018 ◽

Vol 15 (7) ◽

pp. 989-994 ◽

Cited By ~ 1

Author(s):

Ling Li ◽

Bo Su ◽

Yuxiu Liu ◽

Qingmin Wang

Keyword(s):

Sodium Nitrite ◽

Oxidative Coupling ◽

High Resolution Mass Spectrometry ◽

Coupling Reaction ◽

13C Nmr Spectroscopy ◽

Coupling Reactions ◽

Reaction Conditions ◽

1H And 13C Nmr ◽

Oxidative Coupling Reaction ◽

Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

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Selectfluor-induced C(sp2)–O coupling reaction of N-substituted anilines with hydroxylamine derivatives

Organic & Biomolecular Chemistry ◽

10.1039/c8ob01348a ◽

2018 ◽

Vol 16 (33) ◽

pp. 6017-6024 ◽

Cited By ~ 10

Author(s):

Bin Sun ◽

Shi Yin ◽

Xiaohui Zhuang ◽

Can Jin ◽

Weike Su

Keyword(s):

Coupling Reaction ◽

Cross Coupling ◽

Coupling Reactions ◽

Substituted Anilines ◽

Metal Free ◽

Cross Coupling Reactions ◽

Hydroxylamine Derivatives

We developed a novel metal-free method for the construction of C(sp2)–O bonds via oxidative cross-coupling reactions between various N-substituted anilines and hydroxylamine derivatives just using commercially available Selectfluor as an oxidant.

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ChemInform Abstract: Di-tert-butyl Peroxide (DTBP) Promoted Dehydrogenative Coupling: An Expedient and Metal-Free Synthesis of Oxindoles via Intramolecular C(sp2)-H and C(sp3)-H Bond Activation.

ChemInform ◽

10.1002/chin.201604106 ◽

2016 ◽

Vol 47 (4) ◽

pp. no-no

Author(s):

Biplab Mondal ◽

Brindaban Roy

Keyword(s):

Bond Activation ◽

Metal Free ◽

Tert Butyl ◽

Dehydrogenative Coupling ◽

Butyl Peroxide

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Pyridine mediated transition-metal-free direct alkylation of anilines using alcohols via borrowing hydrogen conditions

Chemical Communications ◽

10.1039/d0cc05912a ◽

2020 ◽

Vol 56 (88) ◽

pp. 13607-13610 ◽

Cited By ~ 1

Author(s):

Rajagopal Pothikumar ◽

Venugopal T Bhat ◽

Kayambu Namitharan

Keyword(s):

Transition Metal ◽

Traditional Approach ◽

Metal Catalyst ◽

Transition Metal Catalyst ◽

Metal Free ◽

Borrowing Hydrogen ◽

Activation Of Alcohols ◽

Catalyst Systems ◽

Hydrogen Reactions

Herein, we report aza-aromatics based organic mediators as a readily accessible alternative to the traditional approach of using transition metal catalyst systems for the activation of alcohols in borrowing hydrogen reactions.

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Synthesis of 9-arylalkynyl- and 9-aryl-substituted benzo[b]quinolizinium derivatives by Palladium-mediated cross-coupling reactions

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.14.161 ◽

2018 ◽

Vol 14 ◽

pp. 1871-1884 ◽

Cited By ~ 1

Author(s):

Siva Sankar Murthy Bandaru ◽

Darinka Dzubiel ◽

Heiko Ihmels ◽

Mohebodin Karbasiyoun ◽

Mohamed M A Mahmoud ◽

...

Keyword(s):

Emission Intensity ◽

Binding Constants ◽

Coupling Reaction ◽

Cross Coupling ◽

Coupling Reactions ◽

Sonogashira Coupling ◽

Reaction Conditions ◽

Quadruplex Dna ◽

Cross Coupling Reactions ◽

Sonogashira Coupling Reaction

9-Arylbenzo[b]quinolizinium derivatives were prepared with base-free Suzuki–Miyaura coupling reactions between benzo[b]quinolizinium-9-trifluoroborate and selected benzenediazonium salts. In addition, the Sonogashira coupling reaction between 9-iodobenzo[b]quinolizinium and the arylalkyne derivatives yielded four novel 9-(arylethynyl)benzo[b]quinolizinium derivatives under relatively mild reaction conditions. The 9-(N,N-dimethylaminophenylethynyl)benzo[b]quinolizinium is only very weakly emitting, but the emission intensity increases by a factor >200 upon protonation, so that this derivative may operate as pH-sensitive light-up probe. Photometric and fluorimetric titrations of duplex and quadruplex DNA to 9-(arylethynyl)benzo[b]quinolizinium derivatives revealed a significant binding affinity of these compounds towards both DNA forms with binding constants ofKb= 0.2–2.2 × 105M−1.

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Regiospecific Palladium-Catalyzed Cross-Coupling Reactions Using the Operational Equivalent of 1,3-Dilithiopropyne

Synthesis ◽

10.1055/s-0039-1690895 ◽

2020 ◽

Vol 52 (16) ◽

pp. 2387-2394 ◽

Cited By ~ 1

Author(s):

Jorge A. Cabezas ◽

Natasha Ferllini

Keyword(s):

Coupling Reaction ◽

Cross Coupling ◽

Coupling Reactions ◽

Terminal Alkyne ◽

Copper Iodide ◽

Reaction Conditions ◽

Cross Coupling Reactions ◽

Cross Coupling Reaction ◽

Palladium Catalyzed ◽

High Yields

A regiospecific palladium-catalyzed cross-coupling reaction using the operational equivalent of the dianion 1,3-dilithiopropyne, with aromatic iodides is reported. This reaction gives high yields of 1-propyn-1-yl-benzenes and 2-(propyn-1-yl)thiophenes in the presence of catalytic amounts of palladium(0) or (II) and stoichiometric amounts of copper iodide. No terminal alkyne or allene isomers were detected. Reaction conditions were very mild and several functional groups were tolerated.

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Nitrosonium ion catalysis: aerobic, metal-free cross-dehydrogenative carbon–heteroatom bond formation

Chemical Communications ◽

10.1039/c8cc08328b ◽

2018 ◽

Vol 54 (92) ◽

pp. 13022-13025 ◽

Cited By ~ 21

Author(s):

Luis Bering ◽

Laura D’Ottavio ◽

Giedre Sirvinskaite ◽

Andrey P. Antonchick

Keyword(s):

Bond Formation ◽

Environmentally Benign ◽

Reaction Conditions ◽

Metal Free ◽

Dehydrogenative Coupling ◽

Nitrosonium Ion

Catalytic cross-dehydrogenative coupling of heteroarenes with thiophenols and phenothiazines has been developed under mild and environmentally benign reaction conditions.

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