Interaction of Alkyllithium Compounds with Base. Complex Formation between Ethyllithium and Triethylamine in Benzene

Fluorenyllithium-Lewis Base Complexes

“…8 We believe, however, that the following postulates explain the n.m.r. On the other hand, it is difficult to invoke any resonance or inductive interaction between fluorenyllithium and base that would explain our findings of an upfield shift of the a-protons of T H F and DME, the shifting of not only the a-but also the P-protons of THF, the reversing of the relative positions of the methyl and methylene protons of DME, and finally the appearance of the Li7 signal strongly upfield from the Li7 resonance of lithium aluminum hydride.…”

Evaluation of matrix-assisted laser desorption ionization mass spectrometry for studying the sec-butyllithium and n-butyllithium initiated ring-opening polymerization of hexamethylcyclotrisiloxane (D3)

“…Chain redistribution occurs when a propagating chain reacts with another chain to remove a segment of polymer without terminating the reaction. Cyclization occurs when a propagating chain reacts with itself to form cyclic species (D 3 , D 4 , D 5 , etc.). This type of side reaction is commonly referred to as chain backbiting.…”

“…Organolithium compounds associate in nonpolar solvents to form aggregated species of various degrees due to the electron deficient nature of the lithium atom [4]. N-butyllithium, for example, forms a hexameric aggregate [5] whereas sec-butyllithium forms a tetrameric aggregate [6] in hydrocarbon solvents. Studies involving the reaction of organolithium species with styrene [7,8] and dienes [8,9] have shown that the degree of association directly affects the reactivity.…”

The Constitution of Organolithium Compounds

“…In general, hexameric structures are not observed in the presence of electron donors, although ethyl-lithium remains a hexamer with small amounts of triethylamine in benzene. (14) However, in many cases the tetrameric structures persist even in the presence of strong electron donors such as THF (tetrahydrofuran) and quinuclidine. (65) It is probable that the framework of the tetramers is similar to that found in the absence of electron donors.…”