Efficient Synthesis of a Complete Donor/Acceptor bis(Aryl)diyne Family

Abstract

A facile route to a family of bis(aryl)diynes containing both an electron donating pyridine ring and an electron accepting iodobenzene has been developed. The convergent synthesis involves the coupling of 2-, 3-, or 4-bromopyridine with TMS-acetylene, followed by deprotection to form the first half of the molecule. Similarly, 2-, 3-, or 4-iodoaniline was coupled to TMS-acetylene after protection of the amine group as a diethyltriazine. After conversion of the triazine to an iodine, deprotection of the acetylene and formation of the corresponding bromophenylacetylene, the two halves of the molecule were coupled under Cadiot-Chodkiewicz conditions. Nine new compounds were prepared, each of which was found to thermally polymerize from the melt. None of the compounds underwent photochemical polymerization in the solid-state.

Keywords:

• Diacetylene
• Charge-transfer
• Cross-coupling

Acknowledgment

We thank the donors of the Petroleum Research Fund (Grant No. 35462-B5), the NASA/S.C. Space Grant program and the S.C./EPSCoR program (Grant No. NCC5-575) for supporting this project.