Reaction of lithium diethylamide with an alkyl bromide and alkyl benzenesulfonate: origins of alkylation, elimination, and sulfonation.

ABSTRACT: A combination of NMR, kinetic, and computational methods are used to examine reactions of lithium diethylamide in tetrahydrofuran (THF) with n-dodecyl bromide and n-octyl benzenesulfonate. The alkyl bromide undergoes competitive S(N)2 substitution and E2 elimination in proportions independent of all concentrations except for a minor medium effect. Rate studies show that both reactions occur via trisolvated-monomer-based transition structures. The alkyl benzenesulfonate undergoes competitive S(N)2 substitution (minor) and N-sulfonation (major) with N-sulfonation promoted at low THF concentrations. The S(N)2 substitution is shown to proceed via a disolvated monomer suggested computationally to involve a cyclic transition structure. The dominant N-sulfonation follows a disolvated-dimer-based

SUBMITTER: Gupta L 

PROVIDER: S-EPMC3003873 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature