1,5-Dilithiated Synthetic Building Block, (E)-o-(2′-Lithiovinyl)benzyllithium, by Tellurium-Lithium Exchange of Isotellurochromene

Abstract

E)-o-(2'-Lithiovinyl)benzyllithium 4, generated by the tellurium-lithium exchange of 3-tert-butyl-1H-isotellurochromene (1) with BuLi, reacted with an electrophile and a metal reagent to afford the styrene derivatives 2, 5 and the 1,2-dihydro-2-metalanaphthalenes 8 in moderate to good yield, respectively.

Synthesis and properties of stable 2-metallanaphthalenes of heavier group 14 elements

“…reaction of Tbt-substituted trihalostannanes or trihalogermanes with (E)-o-(2 -lithiovinyl)benzyllithium 5, which can be readily generated from isotellurochromene 4 according to the method reported by Sashida (Scheme 1). 19 Since TbtEX 3 (E = Sn, Ge) were prepared as mixtures of halides (X = Cl and Br), ¶ it is necessary to reduce the initially obtained cyclic halostannanes or halogermanes 6a,b and 7a,b with lithium aluminium hydride. Careful bromination of the resulting hydrostannane 6c and hydrogermane 7c with NBS afforded pure bromostannane 6b and bromogermane 7b in good yields, respectively.…”

Formation of Unusual Iridabenzene and Metallanaphthalene Containing Electron-Withdrawing Substituents

“…Notwithstanding, and to the best of our knowledge, higher metalla-aromatics of the transition elements, viz. metallanaphthalenes or metallaanthracenes, have not been isolated . Following our earlier report on the formation of the bicyclic iridium derivatives 1 and 2 (Chart ) we now wish to describe their transformation under very mild conditions into the irida-aromatic complexes 3 and 4 , respectively.…”

Organodilithium Intermediates as Useful Dianionic Synthons: Recent Advances

“…Thus, the reaction of compounds 215 with 2 equivalents of n-BuLi gave the dilithium derivative 216, which reacted with electrophiles to give styrene derivatives 217. In the case of using electrophiles of the general structure YX2 (Y = R2Si, R2Sn, RSb; X = Cl, Br), 1,2-dihydro-2-metalanaphthalenes 218 were obtained as reaction products (Scheme 49) [108].…”