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Carbolithiation of N-alkenyl ureas and N-alkenyl carbamatesDOI: 10.3762/bjoc.9.70 Keywords: carbamate , carbolithiation , carbometallation , organolithium , stereospecificity , styrene , urea Abstract: N-Alkenyl ureas and N-alkenyl carbamates, like other N-acyl enamines, are typically nucleophilic at their β-carbon. However, by incorporating an α-aryl substituent, we show that they will also undergo attack at the β-carbon by organolithium nucleophiles, leading to the products of carbolithiation. The carbolithiation of E and Z N-alkenyl ureas is diastereospecific, and N-tert-butoxycarbonyl N-alkenyl carbamates give carbolithiation products that may be deprotected in situ to provide a new connective route to hindered amines.
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