Additive-Free Pd-Catalyzed α-Allylation of Imine-Containing Heterocycles
作者:Marko Kljajic、Johannes G. Puschnig、Hansjörg Weber、Rolf Breinbauer
DOI:10.1021/acs.orglett.6b03407
日期:2017.1.6
An additive-free Pd-catalyzed alpha-allylation of different imino-group-ontaining heterocycles is reported. The activation of alpha-CH pronucleophiles (pK(a) (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic investigations suggest an initial allylation of the imine-N followed by a Pd-catalyzed formal aza-Claisen rearrangement.
A New Protocol for the Synthesis of N(1)-Unsubstituted 2-Substituted 2-Imidazolines
作者:Raymond C.F. Jones、Paschalis Dimopoulos
DOI:10.1016/s0040-4020(00)00108-3
日期:2000.3
Lateral metallation at C-2(α) of 1-tert-butoxycarbonyl-2-methyl-2-imidazoline followed by reaction with a range of C-electrophiles and deprotection with TFA reliably affords N(1)-unsubstituted 2-substituted2-imidazolines; P- or Se-electrophiles lead to 2-alkenyl-2-imidazolines via Wadsworth–Emmons or selenoxide elimination protocols.