Highly Strained para-Phenylene-Bridged Macrocycles from Unstrained 1,4-Diketo Macrocycles

Synlett ◽  
2017 ◽  
Vol 28 (17) ◽  
pp. 2205-2211 ◽  
Author(s):  
Bradley Merner ◽  
Nirmal Mitra ◽  
Caroline Merryman
Keyword(s):  
Cross Coupling ◽  
Size Dependent ◽  
Synthetic Strategy ◽  
Grignard Reactions ◽  
Highly Strained

The conversion of macrocyclic 1,4-diketones to highly strained para-phenylene rings has recently been reported by our laboratory. This synthetic strategy represents a non-cross-coupling-based approach to arene-bridged macrocycles, and an alternative to palladium- and nickel-mediated processes. In this Synpacts article we discuss the development of endgame aromatization protocols for the synthesis of increasingly strained arene systems, as well as potential advantages of the macrocyclic 1,4-diketone approach to selectively functionalized benzenoid macrocycles for future complexity building reactions.1 Introduction2 A Non-Cross-Coupling-Based Approach to Arene-Bridged Macro cycles3 Macrocyclic 1,4-Diketones: Streamlined Synthesis and Size-­Dependent Diastereoselective Grignard Reactions4 Dehydrative Aromatization Reactions: A Powerful Tool for Synthesizing Highly Strained para-Phenylene Units5 Conclusion

Symmetry Breaking and the Turn-On Fluorescence of Small, Highly Strained Carbon Nanohoops

2019 ◽  
Author(s):  
Terri Lovell ◽  
Curtis Colwell ◽  
Lev N. Zakharov ◽  
Ramesh Jasti
Keyword(s):  
Symmetry Breaking ◽  
Theoretical Work ◽  
P Systems ◽  
Quantum Yields ◽  
Size Dependent ◽  
New Class ◽  
Carbon Carbon Bond ◽  
Conjugated Macrocycles ◽  
Structural Manipulation ◽  
Highly Strained

<p>[<i>n</i>]Cycloparaphenylenes, or “carbon nanohoops,” are unique conjugated macrocycles with radially oriented p-systems similar to those in carbon nanotubes. The centrosymmetric nature and conformational rigidity of these molecules lead to unusual size-dependent photophysical characteristics. To investigate these effects further and expand the family of possible structures, a new class of related carbon nanohoops with broken symmetry is disclosed. In these structures, referred to as <i>meta</i>[<i>n</i>]cycloparaphenylenes, a single carbon-carbon bond is shifted by one position in order to break the centrosymmetric nature of the parent [<i>n</i>]cycloparaphenylenes. Advantageously, the symmetry breaking leads to bright emission in the smaller nanohoops, which are typically non-fluorescent due to optical selection rules. Moreover, this simple structural manipulation retains one of the most unique features of the nanohoop structures-size dependent emissive properties with relatively large extinction coefficents and quantum yields. Inspired by earlier theoretical work by Tretiak and co-workers, this joint synthetic, photophysical, and theoretical study provides further design principles to manipulate the optical properties of this growing class of molecules with radially oriented p-systems.</p>

Symmetry Breaking and the Turn-On Fluorescence of Small, Highly Strained Carbon Nanohoops

2019 ◽  
Author(s):  
Terri Lovell ◽  
Curtis Colwell ◽  
Lev N. Zakharov ◽  
Ramesh Jasti
Keyword(s):  
Symmetry Breaking ◽  
Theoretical Work ◽  
P Systems ◽  
Quantum Yields ◽  
Size Dependent ◽  
New Class ◽  
Carbon Carbon Bond ◽  
Conjugated Macrocycles ◽  
Structural Manipulation ◽  
Highly Strained

<p>[<i>n</i>]Cycloparaphenylenes, or “carbon nanohoops,” are unique conjugated macrocycles with radially oriented p-systems similar to those in carbon nanotubes. The centrosymmetric nature and conformational rigidity of these molecules lead to unusual size-dependent photophysical characteristics. To investigate these effects further and expand the family of possible structures, a new class of related carbon nanohoops with broken symmetry is disclosed. In these structures, referred to as <i>meta</i>[<i>n</i>]cycloparaphenylenes, a single carbon-carbon bond is shifted by one position in order to break the centrosymmetric nature of the parent [<i>n</i>]cycloparaphenylenes. Advantageously, the symmetry breaking leads to bright emission in the smaller nanohoops, which are typically non-fluorescent due to optical selection rules. Moreover, this simple structural manipulation retains one of the most unique features of the nanohoop structures-size dependent emissive properties with relatively large extinction coefficents and quantum yields. Inspired by earlier theoretical work by Tretiak and co-workers, this joint synthetic, photophysical, and theoretical study provides further design principles to manipulate the optical properties of this growing class of molecules with radially oriented p-systems.</p>

Novel and facile synthesis of 1-benzazepines via copper-catalyzed oxidative C(sp3)–H/C(sp2)–H cross-coupling

2017 ◽  
Vol 53 (90) ◽  
pp. 12229-12232 ◽  
Author(s):  
Rui Wang ◽  
Ruo-Xing Jin ◽  
Zi-Yang Qin ◽  
Kang-Jie Bian ◽  
Xi-Sheng Wang
Keyword(s):  
Cross Coupling ◽  
Facile Synthesis ◽  
Synthetic Strategy

A novel synthetic strategy for the facile construction of 1-benzazepines has been developedviacopper-catalyzed oxidative C(sp3)–H/C(sp2)–H cross-coupling.

ChemInform Abstract: Cross-Coupling Reaction of a Highly Strained Molecule: Synthesis of σ-π Conjugated Tetrahedranes.

ChemInform ◽  
2014 ◽  
Vol 45 (10) ◽  
pp. no-no
Author(s):  
Yuzuru Kobayashi ◽  
Masaaki Nakamoto ◽  
Yusuke Inagaki ◽  
Akira Sekiguchi
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Highly Strained

Towards the Total Synthesis of Schisandrene: Stereoselective Synthesis of the Dibenzocyclooctadiene Lignan Core

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 908-911 ◽  
Author(s):  
K. Babu ◽  
Arramshetti Venkanna ◽  
Borra Poornima ◽  
Bandi Siva ◽  
B. Babu
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Asymmetric Reduction ◽  
Cross Coupling ◽  
Membered Ring ◽  
Stille Reaction ◽  
Reaction Sequence ◽  
Ring Closing Metathesis ◽  
Synthetic Strategy ◽  
First Time

A stereoselective synthesis of the dibenzocyclooctadiene ­lignan core of the natural product schisandrene is described. Starting from readily available gallic acid, the synthetic strategy involves Suzuki–Miyaura cross-coupling, Stille reaction, and ring-closing metathesis (RCM) in the reaction sequence. The required asymmetric center at C-7′ was established by an asymmetric reduction of a keto compound using the Corey–Bakshi–Shibata (CBS) catalyst. In our approach, the eight-membered ring was achieved by RCM for the first time.

A cross-coupling-annulation cascade from peri-dibromonaphthalimide to pseudo-rylene bisimides

2016 ◽  
Vol 3 (11) ◽  
pp. 1435-1442 ◽  
Author(s):  
Sabine Seifert ◽  
David Schmidt ◽  
Frank Würthner
Keyword(s):  
Cross Coupling ◽  
Redox Properties ◽  
Polycyclic Aromatics ◽  
Synthetic Strategy

A novel synthetic strategy based on cascade C–C cross-coupling and C–H arylation afforded structurally unique polycyclic aromatics with desirable optical and redox properties.

Facile synthesis of N-aryl phenothiazines and phenoxazines via Brønsted acid catalyzed C−H amination of arenes

2022 ◽  
Author(s):  
Wang Xia ◽  
Zi-An Zhou ◽  
Jie Lv ◽  
Shao-Hua Xiang ◽  
Yong-Bin Wang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Cross Coupling ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Facile Synthesis ◽  
Synthetic Strategy ◽  
Brönsted Acid ◽  
Acid Catalyzed ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

N-aryl phenothiazines and phenoxazines are of significant importance in various disciplines throughout academia and industry. Conventional synthetic strategy for the construction of these structures centers on transition-metal-catalyzed cross-coupling of aryl...

Cross-Coupling Reaction of a Highly Strained Molecule: Synthesis of σ-π Conjugated Tetrahedranes

2013 ◽  
Vol 52 (41) ◽  
pp. 10740-10744 ◽  
Author(s):  
Yuzuru Kobayashi ◽  
Masaaki Nakamoto ◽  
Yusuke Inagaki ◽  
Akira Sekiguchi
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Highly Strained
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