Selective Utilization of Alkyl Lactates Under Acid and Alkali Regulation and Sustainable Synthesis of Pyridine Compounds from Ammonium Iodide and Chalcone Derivatives

The acid and base environment is used to selectively utilize the bio-based alkyl lactate, after which pyridine compounds are synthesized with ammonium iodide and chalcone derivatives. Using alkyl lactate as a solvent in this method has the advantages of low toxicity, environmental friendliness, and biodegradability. It can also provide a renewable carbon source. A one-pot multicomponent strategy is used to achieve high-value and efficient conversion and utilization of alkyl lactates, and it can perform different CN and CC condensation and coupling reactions. A significant advantage of this method is the selective dehydrogenation of the biomass derivative alkyl lactate, enabling functional switching between green solvents/reaction substrates. Additionally, the recycling of alkyl lactates is realized in the sustainable synthesis process of pyridine heterocycles, utilizing inorganic ammonium salts as "N" sources in conjunction with biomass. More than 40 pyridine compounds are synthesized with yields of up to 90%. This method demonstrates potential for the development and utilization of biomass. It also involves the cleavage of CC bonds in chalcone molecules and the formation of CN bonds. Pyridine heterocyclic compounds are constructed via a [3 + 2 + 1] cycloaddition reaction, which exhibits good functional group tolerance and aligns with the principles of green chemistry.