A General Strategy for N-(Hetero)arylpiperidine Synthesis Using Zincke Imine Intermediates

J Am Chem Soc. 2024 Jan 10;146(1):936-945. doi: 10.1021/jacs.3c11504. Epub 2023 Dec 28.

Abstract

Methods to synthesize diverse collections of substituted piperidines are valuable due to the prevalence of this heterocycle in pharmaceutical compounds. Here, we present a general strategy to access N-(hetero)arylpiperidines using a pyridine ring-opening and ring-closing approach via Zincke imine intermediates. This process generates pyridinium salts from a wide variety of substituted pyridines and (heteroaryl)anilines; hydrogenation reactions and nucleophilic additions then access the N-(hetero)arylpiperidine derivatives. We successfully applied high-throughput experimentation (HTE) using pharmaceutically relevant pyridines and (heteroaryl)anilines as inputs and developed a one-pot process using anilines as nucleophiles in the pyridinium salt-forming processes. This strategy is viable for generating piperidine libraries and applications such as the convergent coupling of complex fragments.