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.
Borane-Catalyzed Reduction of Pyridines via a Hydroboration/Hydrogenation Cascade
Yang, Zhao-Ying,Luo, Heng,Zhang, Ming,Wang, Xiao-Chen
, p. 10824 - 10829 (2021/09/08)
We have developed a method for a B(C6F5)3-catalyzed hydroboration/hydrogenation cascade reduction of pyridines. The method was particularly effective for 2,3-disubstituted pyridines, which generated piperidines in high yields with high cis selectivity. Mechanistic studies indicated that the pyridine substrates and the piperidine products sequentially acted as bases in cooperation with B(C6F5)3to split H2. The broad functional group tolerance of the method allowed its use for the synthesis of some biologically active molecules.
H2 Activation by Non-Transition-Metal Systems: Hydrogenation of Aldimines and Ketimines with LiN(SiMe3)2
Elliott, Daniel C.,Marti, Alex,Mauleón, Pablo,Pfaltz, Andreas
supporting information, p. 1918 - 1922 (2019/01/16)
In recent years, H2 activation at non-transition-metal centers has met with increasing attention. Here, a system in which H2 is activated and transferred to aldimines and ketimines using substoichiometric amounts of lithium bis(trimethylsilyl)amide is reported. Notably, the reaction tolerates the presence of acidic protons in the α-position. Mechanistic investigations indicated that the reaction proceeds via a lithium hydride intermediate as the actual reductant.