3466-80-6Relevant articles and documents
Rapid Synthesis of α-Chiral Piperidines via a Highly Diastereoselective Continuous Flow Protocol
Shan, Chao,Xu, Jinping,Cao, Liming,Liang, Chaoming,Cheng, Ruihua,Yao, Xiantong,Sun, Maolin,Ye, Jinxing
, p. 3205 - 3210 (2022/05/07)
A practical continuous flow protocol has been developed using readily accessible N-(tert-butylsulfinyl)-bromoimine and Grignard reagents, providing various functionalized piperidines (34 examples) in superior results (typically >80% yield and with >90:10 dr) within minutes. The high-performance scale-up is smoothly carried out, and efficient synthesis of the drug precursor further showcases its utility. This flow process offers rapid and scalable access to enantioenriched α-substituted piperidines.
Borenium-Catalyzed Reduction of Pyridines through the Combined Action of Hydrogen and Hydrosilane
Clarke, Joshua J.,Maekawa, Yuuki,Nambo, Masakazu,Crudden, Cathleen M.
supporting information, p. 6617 - 6621 (2021/09/02)
Mesoionic carbene-stabilized borenium ions efficiently reduce substituted pyridines to piperidines in the presence of a hydrosilane and a hydrogen atmosphere. Control experiments and deuterium labeling studies demonstrate reversible hydrosilylation of the pyridine, enabling full reduction of the N-heterocycle under milder conditions. The silane is a critical reaction component to prevent adduct formation between the piperidine product and the borenium catalyst.
α-Functionalization of Cyclic Secondary Amines: Lewis Acid Promoted Addition of Organometallics to Transient Imines
Paul, Anirudra,Seidel, Daniel
supporting information, p. 8778 - 8782 (2019/06/07)
Cyclic imines, generated in situ from their corresponding N-lithiated amines and a ketone hydride acceptor, undergo reactions with a range of organometallic nucleophiles to generate α-functionalized amines in a single operation. Activation of the transient imines by Lewis acids that are compatible with the presence of lithium alkoxides was found to be crucial to accommodate a broad range of nucleophiles including lithium acetylides, Grignard reagents, and aryllithiums with attenuated reactivities.