Functionalized Aminocyclopropanes From Functionalized Organozinc Compounds and N,N-Dialkylcarboxamides
作者:Stefan Wiedemann、Ilan Marek、Armin de Meijere
DOI:10.1055/s-2002-31906
日期:——
Inter- as well as intramolecular competition experiments have been performed to demonstrate that N,N-dialkylcarboxamides react faster than tert-butyl esters with the titanium intermediates formed from ethylmagnesium bromide and methyltitanium triisopropoxide to selectively yield cyclopropylamines rather than cyclopropanols. Thus, functionalized organozinc reagents including a series with tert-butyl ester functionalities could be employed under newly developed conditions to transform N,N-dialkylformamides into chloroalkyl-substituted N,N-dialkylcyclopropylamines (55-67%) and tert-butyl (N,N-dialkylaminocyclopropyl)alkanoates (24-63% yield).
已进行分子间和分子内竞争实验,证明N,N-二烷基羧酰胺比叔丁酯更快与乙烯基溴化镁和甲基三异丙氧基钛形成的钛中间体反应,从而选择性地生成环丙胺而非环丙醇。因此,在新开发的条件下,包括具有叔丁酯功能团的系列在内的功能化有机锌试剂可以用于将N,N-二烷基甲酰胺转化为氯代烷基取代的N,N-二烷基环丙胺(产率55-67%)和叔丁基(N,N-二烷基氨基环丙基)烷酸酯(产率24-63%)。