Stereoselective Intermolecular Carbolithiation of Open-Chain and Cyclic 1-Aryl-1-alkenyl N,N-Diisopropylcarbamates Coupled with Electrophilic Substitution. Observation of p-Carboxylation in a Benzyllithium Derivative
作者:Jan Georg Peters、Michael Seppi、Roland Fröhlich、Birgit Wibbeling、Dieter Hoppe
DOI:10.1055/s-2002-20040
日期:——
1-Aryl-1-alkenyl N,N-diisopropylcarbamates (1) are obtained from alkyl aryl ketones and N,N-diisopropylcarbamoyl chloride (CbCl) by heating with excess pyridine. These undergo facile syn-carbolithiation by alkyllithium/diamine and produce configurationally stable lithiated benzyl carbamates, which have been trapped with different electrophiles. If the reaction is carried out in the presence of chiral
1-芳基-1-烯基 N,N-二异丙基氨基甲酸酯 (1) 由烷基芳基酮和 N,N-二异丙基氨基甲酰氯 (CbCl) 通过与过量吡啶加热而获得。它们通过烷基锂/二胺进行简单的合成碳锂化反应,并产生构型稳定的锂化苄基氨基甲酸酯,其已被不同的亲电子试剂捕获。如果反应在手性二胺如 (-)-sparteine 或 (-)-α-isosparteine 的存在下进行,则观察到适度的对映面分化。