690632-39-4Relevant academic research and scientific papers
Investigation of the [1,5]-hydride shift as a route to nitro-Mannich cyclisations
Anderson, James C.,Chang, Chia-Hao,Corpinot, Mérina K.,Nunn, Michael,Ware, Oliver J.
, (2019/10/14)
Conditions were found for the [1,5]-hydride shift nitro-Mannich reaction that led to the synthesis of 2,3-disubstituted tetrahydroquinolines. Two simple cyclic amine substrates gave diastereomerically pure rearranged products in 65 and 90% yields by refluxing in HFIP. A more general procedure used Gd(OTf)3 as a catalyst and successfully rearranged other cyclic and acyclic amines in 42–84% yield with diastereomeric ratios of 75:25 to >95:5 in favour of the anti-diastereoisomer (9 examples). Two examples of sulphur containing heterocycles gave lower yields of 9 and 25%. Electron withdrawing substituents were shown to have a deleterious effect on the success of the reaction. The results indicated the limitation of the [1,5]-hydride shift nitro-Mannich reaction with respect to the stability of the intermediate iminium ion.
N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion of N-aziridinyl imines
Mahoney, Stuart J.,Fillion, Eric
supporting information; experimental part, p. 68 - 71 (2012/02/04)
Under rhodium catalysis, N-aziridinyl imines provided access to N-fused indolines through non-carbonyl-stabilized rhodium carbenoid C-H insertion. The utility of this methodology for the synthesis of architecturally complex heterocycles was further demonstrated by an expedient total synthesis of ( ±)-cryptaustoline (see scheme). Copyright
