The Effect of Lithium Alkoxides on Deprotonizations by Superbases Made from Butyllithium and Potassium tert-Pentoxide

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Title:The Effect of Lithium Alkoxides on Deprotonizations by Superbases Made from Butyllithium and Potassium tert-Pentoxide
Creators:
Lochmann, Lubomír
Jakubův, Hana
Brandsma, Lambert
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 58, 6, pp. 1445-1451

Abstract

The presence or absence of lithium tert-pentoxide (t-PeOLi) in Superbases, prepared from butyllithium (BuLi) and potasium tert-pentoxide (t-PeOK), affects the metallation rate of toluene only slightly, the rate factors being between 1.0 and 0.3. Thus, lithium alkoxide is not essential for the high reactivity of Superbases. However, the ring-to-side chain metallation ratio is increased in the presence of t-PeOLi. On the other hand, an excess of t-PeOK (molar ratio t-PeOK/BuLi ≥ 3)considerably increases in the rate and yield of the side chain methallation of toluene and suppresses its ring mrtallation. In this way, alkoxides enable some control on regioselectivity in Superbase reactions.

Title:The Effect of Lithium Alkoxides on Deprotonizations by Superbases Made from Butyllithium and Potassium tert-Pentoxide
Creators:
Lochmann, Lubomír
Jakubův, Hana
Brandsma, Lambert
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:58
Number:6
Page Range:pp. 1445-1451
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19931445UNSPECIFIED
ID Code:263
Item Type:Article
Deposited On:06 Feb 2009 16:59
Last Modified:06 Feb 2009 15:59

Citation

Lochmann, Lubomír; Jakubův, Hana; Brandsma, Lambert (1993) The Effect of Lithium Alkoxides on Deprotonizations by Superbases Made from Butyllithium and Potassium tert-Pentoxide. Collection of Czechoslovak Chemical Communications, 58 (6). pp. 1445-1451. ISSN 0010-0765

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