Building Blocks for the Construction of Large Chloro-Functionalized, Hexagonal Oligophenylene Cycles

Abstract

The synthesis of a variety of kinked oligophenylene building blocks is described. The synthetic strategy is repetitive, utilizes the Suzuki cross‐coupling protocol, and involves potentially bifunctional building blocks (modules) which carry one functional group for coupling and one group which serves as place holder. After the coupling, the placeholder is converted into a coupling functionality for the next growth step. The building blocks also carry chloro‐substituents which are unaffected by all transformations. For one of the large building blocks it is shown that it actually can be cyclized into an oligophenylene macrocycle with a chloro‐substituent at each corner and a pair of hexyl chains at each side.

An Approach to the Total Synthesis of the Marine Ascidian Metabolite Perophoramidine via a Halogen-Selective Tandem Heck/Carbonylation Strategy

“…Our synthetic strategy for perophoramidine is based on effecting a tandem Heck/carbonylation reaction in the presence of the halogens found in 1 . Although one would expect that oxidative insertion of palladium into an aryl iodine bond would be faster than that into aryl chlorine or bromine bonds, we were unable to find any examples of an intramolecular Heck reaction with this type of internal competition where different types of halogens are present in the same molecule . In addition, we needed to test the compatibility of a C ring ortho substituent with our key transformation, and to investigate the introduction of the second quaternary center at C4 with the requisite stereochemistry.…”

On-Surface Synthesis and Characterization of Honeycombene Oligophenylene Macrocycles

“…There are numerous examples for the synthesis of conjugated macrocycles in solution, , most of which use a combination of arylene and ethynylene building blocks to generate shape-persistent rings. − Macrocycles consisting exclusively of phenylene groups have rarely been made. , A drawback of the solution-based approach is that the large molecules and their precursors carry spacious substituents (typically alkyl chains with 6 to 12 carbon atoms), which are necessary to achieve sufficient solubility during synthesis, but are disadvantageous in other respects, because they can prevent efficient π-orbital overlap in molecular organic semiconductors, resulting in reduced charge carrier mobility, affect the two- or three-dimensional crystallization, and may have adverse effects in molecular machines . An illustrative example is the C 60 -wheeled “nanocar” molecule with its 12 C 10 H 21 chains .…”

Nano-Saturn: Energetics of the Inclusion Process of C60 into Cyclohexabiphenylene

“…Because of its structural analogy to CPP, it is likely to synthesize CBP using a similar procedure to that for CPP . A previous experiment shows that cyclic oligophenylene molecules with alkyl groups were synthesized using a cross-coupling technique. , Note that the cyclic oligophenylene molecules with chemical functional groups are not suitable for the use of the nano-Saturn’s ring because of the steric hindrance of the functional groups.…”