Synthesis of [Ethylene-1-(η 5-4,5,6,7-tetrahydro-1-indenyl)-2-(η5-4′ ,5′,6′,7′-tetrahydro-2′-indenyl)]titanium Dichloride, the Elusive Isomer of the Brintzinger-Type ansa-Titanocenes

Patrick A. Kelly, Gideon O. Berger, Justin K. Wyat, Michael H. Nantz

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

We present a short synthesis of 1-(2-indenyl)-2-(3-indenyl)ethane (5) and a method for its conversion to the ansa-metallocene [ethylene(η 5-inden-1-yl)(η5-inden-2-yl)] titanium dichloride (13). The synthetic strategy applied to prepare bisindene 5 relies on the efficient alkylation of 2-(phenylsulfonyl)-indane followed by HMPA-assisted E1cB-elimination of phenylsulfinate. This tandem sequence circumvents the predisposition of indene to undergo C(1)-alkylation and enables access to C(2)-substituted indenes. The key step in the synthesis of the title ansa-titanocene (4) features a previously unreported equilibration step to generate the bis(indenide anion) of 5. Complexation with TiC1 4·(THF)2 followed by hydrogenation of the product metallocene furnishes ansa-titanocene 4.

Original languageEnglish (US)
Pages (from-to)8447-8452
Number of pages6
JournalJournal of Organic Chemistry
Volume68
Issue number22
DOIs
StatePublished - Oct 31 2003

ASJC Scopus subject areas

  • Organic Chemistry

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