116376-07-9Relevant academic research and scientific papers
Palladium-Catalyzed Migratory Insertion of Isocyanides for Synthesis of C-Phosphonoketenimines
Yang, Qiang,Li, Chong,Cheng, Ming-Xing,Yang, Shang-Dong
, p. 4715 - 4719 (2016)
An efficient method for the synthesis of C-phosphonoketenimines through palladium-catalyzed migratory insertion of isocyanides has been developed for the first time. This procedure tolerates wide functional groups and has a good atom economy. Further tran
α-Oxo-Ketenimines from Isocyanides and α-Haloketones: Synthesis and Divergent Reactivity
Mamboury, Mathias,Wang, Qian,Zhu, Jieping
supporting information, p. 12744 - 12748 (2017/09/25)
The palladium-catalyzed reaction of α-haloketones with isocyanides afforded α-oxo-ketenimines through β-hydride elimination of the β-oxo-imidoyl palladium intermediates. Reaction of these relatively stable α-oxo-ketenimines with nucleophiles such as hydrazines, hydrazoic acid, amines, and Grignard reagent afforded pyrazoles, tetrazole, β-keto amidines, and enaminone, respectively, with high chemoselectivity. Whereas amines attack exclusively on the ketenimine functions, the formal [3+2] cycloaddition between N-monosubstituted hydrazines and α-oxo-ketenimines was initiated by nucleophilic addition to the carbonyl group.
Formation of Polycyclic Dimers from Vinyl Nitroxides and Their Dissociation and Isomerization
Aurich, Hans Guenter,Bubenheim, Otto,Kessler, Wilfried,Mogendorf, Klaus-Dieter
, p. 4997 - 5004 (2007/10/02)
The ambiphilic vinyl nitroxides (VN) 6 dimerize, affording either tricyclic dimers (TRI-DI) 8 or bicyclic dimers (BI-DI) 7.Formation of 8 is rationalized by C-C bond formation followed by an intramolecular (3 + 2 + 2) cycloaddition involving one nitrone and two carbonyl groups, whereas 7 must arise from O-C bond formation followed by an intramolecular (3 + 2) cycloaddition of nitrone and alkene moiety.Since the BI-DIs 7 are the thermodynamically more stable dimers, the course of the reaction depends on the question of whether it is possible to overcome the activation barrier for its formation.The crucial reaction step, the 1,3 dipolar cycloaddition involving the nitrone and alkene moiety, is favored by N-phenyl substitution and retarded by N-tert-butyl substitution of the nitrone group.Thus, BI-DIs 7 arise from N-phenyl-substituted VNs, whereas VNs with R1 = tert-butyl yield TRI-DIs 8 at room temperature.Most of the TRI-DIs 8 dissociate at room temperature or slightly elevated temperatures.Dissociation is favored either by steric congestion of 8 or by enhanced stabilization of the acyl group R3CO of the VNs 6.Tetracyclic dimers (TET-DI) 12 arise from TRI-DIs 8 in refluxing methanol or in the presence of acids at room temperature.Isomerization in aprotic solvents in the absence of acids requires higher temperatures.Under these conditions formation of TET-DIs 12 is frequently accompanied by formation of BI-DIs 7 which must be formed via the VNs 6.
