Stereoselective strategies for the construction of polysubstituted piperidinic compounds and their applications in natural products’ synthesis
Résumé
Nitrogen-encompassing bioactive molecules can be regarded as the most frequently cited moieties, occurring either as natural products or as synthetically constructed chemical entities. One such framework which is abundantly found in both natural and synthetic chemical structures is the piperidinic core. A functionalized piperidinic core, either in natural products or in pharmaceuticals, is one of those immensely prevalent moieties. The piperidine frame can be seen in innumerable drug entities and this can be attributed to various reasons like the spacing obtained by piperidine structural conformers during the drug–receptor interactions, and solubility enhancement, hence resulting in improved pharmacokinetics and, most importantly, making the drug architecture metabolically stable. Further tapering down, 2, 4 and 6 substituted piperidines in general and with chiral centres in specific have attracted a substantial amount of attention in the recent past. This can be attributed to their diverse biological activities like analgesic, antimicrobial, sedative, antiasthmatic etc. In this communication, we aim to sum up and review all the reported methods since 2009 for the construction of the polysubstituted piperidinic core. Each method cited herein is exemplified with the synthesis of a natural compound and particularly alkaloids.