Substituent Effects in the Preparation of Naphthacenes by the Coupling Reaction of Diyne‐Derived Zirconacyclopentadienes with Tetraiodobenzene

Abstract

The synthesis of a series of substituted naphthacene derivatives through the coupling reaction of zirconacyclopentadienes with diiodobenzenes is reported. A reaction of bis(propargyl)benzenes with zirconacene dibutyl afforded the corresponding tricyclic zirconacyclopentadienes, which reacted with o-diiodobenzenes to afford the corresponding dihydronaphthacenes. The yields of the coupling reactions were dependent on the substituents on both of the zirconacycles and o-diiodobenzenes. The reactions of diphenyl-substituted zirconacycles gave higher yields than those of the alpha,alpha'-dialkyl-substituted derivatives. The iodide functions thus introduced allowed further introduction of substituents by well-established cross-coupling reactions after construction of the naphthacene skeletons.

9‐Stannafluorenes: 1,4‐Dimetal Equivalents for Aromatic Annulation by Double Cross‐Coupling

“…Considering that 1,4‐M 2 can be readily prepared from the corresponding 1,4‐X 2 and, in particular, the structural variation of available 1,2‐X 2 is much broader than that of 1,2‐M 2 : thus mode B‐type annulation could greatly expand the repertoire of accessible PAHs. However, the precedents of mode B‐type annulation were limited to only the reactions of 2,2′‐diborylbiphenyls,4a zirconacyclopentadienes,4b–d [Zr(2,2′‐biphenyldilyl) 3 ][Li⋅(THF) 4 ] 2 ,4e–g 2,2′‐distannylbinaphthyl,4h and 1,4‐dilithiobutadienes4j with 1,2‐dihalobenzenes, and there is still much room for improvement in the scope of the substrates and reagents, yields, and reaction conditions.…”

Zirconocene-mediated selective synthesis of 1,4-bis(alkynyl)benzenes

“…5–7 Although the synthesis, properties, and applications of benzene derivatives have been studied for a long time, there are still only a few reports on the selective synthesis of 1,4-bis(alkynyl)benzenes. 8–10 The synthesis of benzene derivatives by cycloaddition of zirconacyclopentadienes to a third molecular alkyne is well known, 11 and chemists initially considered it as a potential way to prepare 1,4-bis(alkynyl)benzenes through the 2,5-bis(alkynyl)zirconacyclopentadiene C (Eq. 1).…”

Zirconium-Mediated Synthesis of Multi-substituted Dibenzosilole and Benzonaphthosilole Derivatives

“…In our previous studies, zirconacyclopentadienes have been used as intermediates for the synthesis of naphthacene derivatives, multi-substituted benzenes, and 1,2,3,4-tetraalkyl-1,4-diarylbutadienes [20][21][22]. In these studies, zirconacyclopentadienes were formed using silicon-free terminal alkynes and internal alkynes as starting materials.…”