Sign in  |  Register
Cart

CSJ Journals

▾
  • -

2019, Vol.92, No.12

2019-2029

Methylarene-Based PAH Synthesis via Domino Cyclization of 1,1-Difluoro-1-alkenes

Kohei Fuchibe ,Go Takao ,Hiroki Takahashi ,Shiori Ijima , and Junji Ichikawa *
Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571, Japan
https://doi.org/10.1246/bcsj.20190252

Tools
PDF (1641K)
Abstract

Polycyclic aromatic hydrocarbons (PAHs) containing 4–7 benzene rings were synthesized via a methylarene-based protocol. Trimethyl[2-(trifluoromethyl)allyl]silane was electrophilically benzylated with Ar1CH2Br (prepared from Ar1CH3) to afford 2-trifluoromethyl-1-alkenes that were in turn nucleophilically benzylated with Ar2CH2Li (prepared from Ar2CH3) through an SN2′-type reaction to produce 1,1-difluoroethylenes, which are cyclization precursors bearing two 2-arylethyl groups. Magic acid efficiently promoted the domino Friedel–Crafts-type cyclization of these precursors, followed by dehydrogenation that enabled the connection among two aryl groups (Ar1 and Ar2) by forming two benzene rings between them, facilitating the synthesis of the desired higher-order PAHs. With the proposed protocol, the combination of even a limited number of methylarenes can yield a variety of PAHs in diverse configurations.

figure

Polycyclic aromatic hydrocarbons (PAHs) were synthesized from two methylarene molecules. Trimethyl[2-(trifluoromethyl)allyl]silane was treated with Ar1CH2Br derived from Ar1CH3 to afford 2-trifluoromethyl-1-alkenes, which underwent an SN2′-type reaction with Ar2CH2Li generated from Ar2CH3 to produce 1,1-difluoro-1-alkenes (cyclization precursors); their FSO3H·SbF5-promoted domino cyclization followed by dehydrogenation yielded PAHs. The combination of even a limited number of methylarenes resulted in various higher order PAHs.

<< Previous Oxygen-Deficient TiO2-δ Synthesized from MIL-125 Metal-Organic Framework for Photocatalytic Dye Degradation Next >> Composite Tetraheteroarylenes and Related Higher Cyclic Oligomers of Heteroarenes Produced by Palladium-Catalyzed Direct Coupling

Select Issues

▾
  • -

Search for Articles

Advanced

Saved Search

Please login to view your saved searches.

Top Accessed Articles

Most Cited

Related Articles

  1. Reactions of (E)-2-Iodo-1-tosyl-1-alkenes as Useful Synthetic Intermediates
  2. Synthesis of 1-Azaazulenes from Cycloheptatrienylmethyl Ketone O-Pentafluorobenzoyloximes by Palladium-Catalyzed Cyclization and Oxidation
  3. Synthesis of Polycyclic Imines by Palladium-Catalyzed Domino Cyclization of Di- and Trienyl Ketone O-Pentafluorobenzoyloximes
  4. TOTAL SYNTHESIS OF (±)-AKLAVINONE VIA BIOMIMETIC ROUTE. APPLICATION OF AN EFFICIENT “ZIPPER” REACTION—STEREOCONTROLLED ONE-STEP BICYCLO-CYCLIZATION
  5. Unsymmetrical Tetra-Acceptor-Substituted Alkenes as Polyfunctionalized Building Blocks: A Divergent Synthesis of Densely Functionalized Pyrrolizines
MANAGE YOUR ALERTS
RECOMMEND TO LIBRARY