The Construction of Highly Substituted Piperidines via Dearomative Functionalization Reaction

Nitrogen heterocycles play a vital role in pharmaceuticals and natural products, with the six-membered aromatic and aliphatic architectures being commonly used. While synthetic methods for aromatic N-heterocycles are well-established, the synthesis of their aliphatic functionalized analogues, particularly piperidine derivatives, poses a significant challenge. In that regard, we propose a stepwise dearomative functionalization reaction for the construction of highly decorated piperidine derivatives with diverse functional handles. We also discuss challenges related to site-selectivity, regio- and diastereoselectivity, and provide insights into the reaction mechanism through mechanistic studies and density functional theory computations. The stepwise dearomative functionalization reaction of pyridines generates highly substituted piperidines, featuring diverse functional handles, with excellent site-, regio-, and diastereoselectivity. The origin of the unprecedented selectivities and additional insights into the reaction mechanism are discussed based on combined experimental mechanistic studies and density functional theory computations.+image

Automated summary

Nitrogen heterocycles, including aromatic and aliphatic architectures, play an important role in pharmaceuticals and natural products. This article proposes a stepwise dearomative functionalization reaction for synthesizing highly decorated piperidine derivatives. The challenges related to site-selectivity, regio- and diastereoselectivity are discussed, and the reaction mechanism is studied through experiments and computational calculations.