Simple ring-closing metathesis approach for synthesis of PA11, 12, and 13 precursors from oleic acid

Due to the concerns over limited fossil resources and increasing CO₂ emissions, there is a strong interest in use of renewable resources in production of valuable synthetic materials. PA11, 12, and 13, more commonly known as Nylon, are high-strength polymers that find use in various industrial sectors. They are traditionally produced from petroleum-derived material or exotic fatty acids using reaction sequences that involve 4-6 steps. Herein we report a simple three-step synthesis of these polyamide precursors from oleic acid, an abundant natural fatty acid available from common plant sources as well as oleaginous micro-organisms such as microalgae. This approach represents the first example where ring-closing metathesis was used for the key C-C bond forming step, featuring introduction of amine functionality required in the final product. Our versatile approach allows preparation of nylon precursors of various chain-lengths from a single starting material for economical and sustainable production of these polymers.