Synthesis of Heterocycles via X—H Bond Addition to Diynes

Heteroles (heteroatom-substituted cyclopentadienes) are an important class of compounds that have been utilized as synthetic intermediates, biologically active substances, ligands, functional materials, and building units for supramolecular architectures. In particular, some heteroles have received considerable attention because of the interesting electronic and optical properties associated with the orbital interaction between the butadiene orbitals and the atomic orbitals on heteroatoms [1]. 

A number of synthetic methods have developed for construction of the heterole skeletons. The most straightforward and atom-economical method for the synthesis of 2,5-disubstituted heteroles is the double addition of X—H bonds across 1,3-diynes, albeit it requires trans addition to the carbon-carbon triple bonds. Thiophenes [2], selenophenes [3], teUurophenes [4], phospholes [5], arsoles [6], and stannoles [7] have been synthesized by using this method without the aid of catalysts  

The rest of the heteroles require transition-metal catalysts for their formation, which are discussed in this chapter. 

Transition-Metal-Mediated Aromatic Ring Construction, First Edition. Edited by Ken Tanaka. 2013 John Wiley Sons, Inc. Published 2013 by John Wiley Sons, Inc. 

20 SYNTHESIS OF PYRROLES AND FURANS VIA DOUBLE TRANS ADDITION TO 1,3-DIYNES 

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T. Matsuda, Synthesis of heterocycles via X—H bond addition to diynes. in Transition-Metal-Mediated Aromatic Ring Construction. (Ed K. Tanaka), p. 537. John Wiley Sons, Ltd., New York, 2013. 

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