Harder, Sjoerd; Boersma, Jaap; Brandsma, Lambert; Kanters, Jan A.; Duisenberg, Albert J. M.; Van Lenthe, Joop H.:

Isolation and crystal structure of a presumed intermediate in the reaction of an organolithium compound with an epoxide.

In: Organometallics, Jg. 9 (1990) ; Nr. 2, S. 511-516
ISSN: 0276-7333
Zeitschriftenaufsatz / Fach: Chemie
The organolithium-epoxide complexes tetrakis(1-lithio-2-methoxybenzene)bis(ethylene oxide) and tetrakis(1-lithio-2-methoxybenzene)bis(propylene oxide), which are thought to be intermediates in the b-hydroxyalkylation of organolithium compds., have been isolated and characterized. NMR studies on these complexes in nonpolar solvents such as C6H6 and PhMe provide evidence for epoxide O to Li coordination. Addnl., the propylene oxide complex has been characterized by single-crystal x-ray diffraction at 100 K. The structure consists of a tetrameric aggregate of 1-lithio-2-methoxybenzene and two disordered propylene oxide mols., which coordinate to Li as external Lewis bases. Since ab initio calcns. (RHF; SV 3-21G) show the activation of the epoxide by Li coordination to be very small, the question of whether such complexes are intermediates in the nucleophilic ring opening of epoxides remains unanswered.

Dieser Eintrag ist freigegeben.