title: Variation in the site of lithiation of 2-(2-methylphenyl)ethanamine derivatives.
abstract: Unexpectedly, lithiation of N'-(2-(2-methylphenyl)ethyl)-N,N-dimethylurea with 3 equiv of n-butyllithium in anhydrous THF at 0 °C takes place on the nitrogen and on the CH(2) next to the 2-methylphenyl ring (α-lithiation). The lithium reagent thus obtained reacts with various electrophiles to give the corresponding substituted derivatives in excellent yields. Similarly, lithiation of N-(2-(2-methylphenyl)ethyl)pivalamide under similar reaction conditions followed by reaction with benzophenone as a representative electrophile gave the corresponding α-substituted product in high yield. Surprisingly, no products resulting from lateral lithiation were observed under the conditions tried, which sharply contrasts with the reported results for lateral lithiation of tert-butyl (2-(2-methylphenyl)ethyl)carbamate.
authors.affiliation: School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK. smithk13@cardiff.ac.uk
authors.forename: Keith
authors.initials: K
authors.lastname: Smith
authors.forename: Gamal A
authors.initials: GA
authors.lastname: El-Hiti
authors.forename: Mohammed B
authors.initials: MB
authors.lastname: Alshammari
mesh_terms: D001554:Benzene / Q000737:chemistry*; D001665:Binding Sites; D005021:Ethylamines / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: C581340:2-(2-methylphenyl)ethanamine; D005021:Ethylamines; D008094:Lithium; D001554:Benzene