Three-component allylation and cyanation utilizing a ketone and an N-methoxyamine are reported. The high nucleophilicity of the N-methoxyamine and high electrophilicity of the corresponding iminium ion enable the concisesynthesis of α-trisubstitutedamines in a single step.
An Improved and Stereoselective Route to All-cis-2,6-Disubstituted 4-Hydroxypiperidines from Accessible 4-Substituted 4-N-Benzylaminobut-1-enes
作者:Alexey Varlamov、Vladimir Kouznetsov、Fedor Zubkov、Alexey Chernyshev、Olga Shurupova、Leonor Y. Vargas Méndez、Alirio Palma Rodríguez、Juliette Rivero Castro、Alfredo J. Rosas-Romero
DOI:10.1055/s-2002-25770
日期:——
The reaction between allylmagnesium bromide and imines 5a-l leads to the corresponding 4-substituted 4- N-benzy- laminobut-1-enes 6a-l, which were oxidized in a regioselective manner to the alkenylnitrones 7a-l. The intramolecular 1,3-dipolar cycloaddition of these nitrones gave 2-spiroannulated or 2-substi- tuted 6-exo-phenyl-1-aza-7-oxabicyclo(2.2.1)heptanes 8a-j. Re- ductive cleavage of the N-O
Abstract A free-radical-based protocol for the construction of the azaspirocyclic core of the natural product perhydrohistrionicotoxin is described. The adopted strategy is based on the use of an enantiomerically pure allylamine bearing a properly substituted cyclohexane at the allylic position as a radical acceptor. An unexpected reductive atom transfer radical addition reaction, followed by lactamization
Synthesis of nitrogen-containing spirocyclic scaffolds via aminoallylation/RCM sequence
作者:Evgeny Prusov、Martin E. Maier
DOI:10.1016/j.tet.2007.07.083
日期:2007.10
were subsequently alkylated with bromomethylmethacrylate resulting in propenyl-butenyl substituted amine derivatives. Basic amines such as 4 or 10 were cyclized with the Grubbs 2nd generation catalyst in the presence of pTsOH. Carbamate derivatives could be converted to tetrahydropiperidine derivatives with the same catalyst. It could be shown that the acrylate functionality can be degraded to the ketone
Asymmetric Synthesis of Six-Membered Cyclic Sulfamides via
Palladium-Catalyzed Alkene Carboamination Reactions
作者:John Wolfe、Zachary Garlets
DOI:10.1055/s-0036-1591574
日期:2018.11
Abstract The asymmetricsynthesis of six-membered cyclic sulfamides via palladium-catalyzedalkenecarboaminationreactions of N-homoallylsulfamides with aryl halides is described. High levels of enantioselectivity were obtained with a catalyst composed of Pd2dba3 and (S)-Siphos-PE. The asymmetricsynthesis of six-membered cyclic sulfamides via palladium-catalyzedalkenecarboaminationreactions of N-homoallylsulfamides