sc3c00886_si_001.pdf (1.28 MB)
Efficient Production of Valuable Aromatic N‑Heterocycles from Bio-Polyols by Heterogeneous Catalysis via Controlling Unstable Intermediate Conversion
journal contributionposted on 2023-06-12, 11:35 authored by Feng Yu, Feng-Shou Xiao
Efficient and controllable conversion of renewable polyols to valuable N-containing products by heterogeneous catalysis, especially under relativley mild conditions (<200 °C), remains a significant challenge. Here, we develop a method for one-step efficient production of 2-methylquinoxalines (2-MQs), a type of high-value aromatic N-heterocycles, directly from polyols in the presence of supported Pt dehydrogenation catalyst through controllably in situ trapping reactive pyruvaldehyde (PA) intermediate by aryl-1,2-diamine at the temperature of only 140 °C. The presence of aryl-1,2-diamine not only enabled the formation of 2-MQs, but also markedly enhanced the polyols’ carbon utilization to near-quantitative (>98 C%) level. More importantly, organic solvent-enabled kinetics control of competitive reactions associated with PA transformation, i.e., the condensation with aryl-1,2-diamine to produce 2-MQs and the Cannizzaro reaction to form lactic acid, allowed to access the desired 2-MQs in a controllable manner with yields ranging from 12 C% to 81 C%. The application of this approach to attain diverse 2-MQs and analogues of interest in pharmaceutical industry has been demonstrated.
form lactic acidcompetitive reactions associatedalso markedly enhanced81 c %.140 ° c>- containing productsstep efficient productionenabled kinetics controlattain diverse 2efficient production12 c>- heterocyclesyields rangingvalue aromaticsignificant challengeproduce 2pharmaceutical industryorganic solventn heterogeneous catalysise .,desired 2controllable mannercontrollable conversioncannizzaro reaction>‑ heterocycles