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Lateral lithiation of N,N′-diaryl ureas

2006; Elsevier BV; Volume: 47; Issue: 39 Linguagem: Inglês

10.1016/j.tetlet.2006.07.134

1873-3581

Jonathan Clayden, Jérémy Dufour,

Chemical Reaction Mechanisms

Aromatic ureas bearing N-(2-alkylaryl) groups may be laterally lithiated by treatment with sec-butyllithium. Quenching with a range of electrophiles yields functionalised aryl ureas in excellent yield. Lateral lithiation is favoured when the urea nitrogen adjacent to the aromatic ring in question is alkylated, and when competitive lithiations of such a ring are possible, lateral lithiation is more favourable than the alternative ortholithiation.