1207280-46-3Relevant academic research and scientific papers
Palladium-Catalyzed Cascade Carbonylation to α,β-Unsaturated Piperidones via Selective Cleavage of Carbon–Carbon Triple Bonds
Beller, Matthias,Ge, Yao,Jackstell, Ralf,Jiao, Haijun,Spannenberg, Anke,Yang, Ji,Ye, Fei
supporting information, p. 22393 - 22400 (2021/09/08)
A direct and selective synthesis of α,β-unsaturated piperidones by a new palladium-catalyzed cascade carbonylation is described. In the presented protocol, easily available propargylic alcohols react with aliphatic amines to provide a broad variety of interesting heterocycles. Key to the success of this transformation is a remarkable catalytic cleavage of the present carbon–carbon triple bond by using a specific catalyst with 2-diphenylphosphinopyridine as ligand and appropriate reaction conditions. Mechanistic studies and control experiments revealed branched unsaturated acid 11 as crucial intermediate.
Transition-Metal-Free Multiple Functionalization of Piperidines to 4-Substituted and 3,4-Disubstituted 2-Piperidinones
Chamorro-Arenas, Delfino,Nolasco-Hernández, Alejandro A.,Fuentes, Lilia,Quintero, Leticia,Sartillo-Piscil, Fernando
supporting information, p. 4671 - 4676 (2020/03/10)
Remote and multiple functionalization of piperidines without the use of transition-metal catalysts and elaborate directing groups is one of the major challenges in organic synthesis. Herein is reported an unprecedented two-step protocol that enables the multiple functionalization of piperidines to either 4-substituted or trans-3,4-disubstituted 2-piperidones. First, by exploiting the duality of TEMPO reactivity, which under oxidative and thermal conditions fluctuates between cationic and persistent-radical form, a novel multiple C(sp3)-H oxidation of piperidines to α,β-unsaturated 2-piperidones was developed. Second, the intrinsic low reactivity of the unsaturated piperidones toward conjugated Grignard additions was overcome by using trimethylsilyl chloride (TMSCl) as Lewis acid. Subsequently, conjugated Grignard addition/electrophilic trapping protocol provided substituted 2-piperidone intermediates, some of which were then transformed into pharmaceutical alkaloids.
Preparation of aα,β-Unsaturated Lactams through intramolecular electrophilic carbamoylation of Alkenes
Yasui, Yoshizumi,Kakinokihara, Issei,Takeda, Hiroshi,Takemoto, Yoshiji
experimental part, p. 3989 - 3993 (2010/03/24)
A general, synthetic method for the preparation of α, βunsaturated lactams startingsei from alkenylchloroformamides has been developed. The reaction was complete within five minutes at 150 °C in N-methylpyrrolidone with a catalytic amount of HBr under mic
