Modular Synthesis of Bicyclic and Tricyclic (Aza‐) Arenes from Nucleophilic (Aza‐)Arenes with Electrophilic Side Arms via [4+2] Annulation Reactions

Wenbo Huang; Shaomin Chen; Jian Yang; Ahmed El‐Harairy; Xin Wang; Minghao Li; Yanlong Gu

doi:10.1002/adsc.201900425

Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

10.26434/chemrxiv.7878065.v1 ◽

2019 ◽

Author(s):

Evan Gardner ◽

Caitlyn Cobb ◽

Jeffery A. Bertke ◽

Timothy H. Warren

Keyword(s):

Single Crystal ◽

Copper Hydroxide ◽

X Ray ◽

Modular Synthesis ◽

Pendant Arm ◽

Copper Center ◽

Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands XpyMeTpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [XpyMeTpCu]2(𝜇–OH)2(6a–6e) complexes were synthesized from the corresponding XpyMeTpCu–OAc (5a–5e) complexes. Single crystal X-ray structures of three new dinuclear [XpyMeTpCu]2(𝜇–OH)2complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric DMAPMeTpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈OH frequencies that tracks with the H-bond accepting ability of the pendant arm.

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Tris(pyrazolyl)borate Copper Hydroxide Complexes Featuring Tunable Intramolecular H-bonding

10.26434/chemrxiv.7878065 ◽

2019 ◽

Author(s):

Evan Gardner ◽

Caitlyn Cobb ◽

Jeffery A. Bertke ◽

Timothy H. Warren

Keyword(s):

Single Crystal ◽

Copper Hydroxide ◽

X Ray ◽

Modular Synthesis ◽

Pendant Arm ◽

Copper Center ◽

Vibrational Studies

A modular synthesis provides access to a series of new tris(pyrazolyl)borate ligands XpyMeTpK that possess a single functionalized pendant pyridyl (py) or pyrimidyl (pyd) arm designed to engage in tunable intramolecular H-bonding to metal–bound functionalities. To illustrate such H-bonding interactions, a series of [XpyMeTpCu]2(𝜇–OH)2(6a–6e) complexes were synthesized from the corresponding XpyMeTpCu–OAc (5a–5e) complexes. Single crystal X-ray structures of three new dinuclear [XpyMeTpCu]2(𝜇–OH)2complexes reveal H-bonding between the pendant heterocycle and bridging hydroxide ligands while the donor arm engages the copper center in an unusual monomeric DMAPMeTpCu–OH complex. Vibrational studies (IR) of each bridging hydroxide complex reveal reduced 𝜈OH frequencies that tracks with the H-bond accepting ability of the pendant arm.

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Synthesis of Pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by Alkyne-Carbonyl Metathesis

Synthesis ◽

10.1055/s-0040-1706105 ◽

2020 ◽

Author(s):

Peter Ehlers ◽

Peter Langer ◽

Marian Blanco Ponce ◽

Silvio Parpart ◽

Alexander Villinger ◽

...

Keyword(s):

Heterocyclic Compounds ◽

Metathesis Reaction ◽

Synthetic Methodology ◽

Facile Synthesis ◽

Reaction Conditions ◽

One Pot ◽

Metal Free ◽

Modular Synthesis

AbstractA concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.

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Modular Synthesis of 3-Substituted Isocoumarins via Silver-Catalyzed Aerobic Oxidation/6-Endo Heterocyclization of ortho-Alkynylbenzaldehydes

Organic & Biomolecular Chemistry ◽

10.1039/d1ob01065d ◽

2021 ◽

Author(s):

Hao Wu ◽

Yi-Chun Wang ◽

Andrey Shatskiy ◽

Qiu-Yan Li ◽

Jian-Quan Liu ◽

...

Keyword(s):

Aerobic Oxidation ◽

Modular Synthesis ◽

Convenient Access

A method involving silver-catalyzed aerobic oxidation/6-endo heterocyclization of ortho-alkynylbenzaldehydes to yield 3-substituted isocumarins is described. The developed protocol allows convenient access to a range of synthetically useful 3-substituted isocoumarins and...

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