5782-71-8Relevant academic research and scientific papers
Exploiting Synergistic Catalysis for an Ambient Temperature Photocycloaddition to Pyrazoles
Lakeland, Christopher P.,Watson, David W.,Harrity, Joseph P. A.
, p. 155 - 159 (2019/12/11)
Sydnone-based cycloaddition reactions are a versatile platform for pyrazole synthesis, however they operate under harsh conditions (high temperature and long reaction times). Herein we report a strategy that addresses this limitation utilizing the synergistic combination of organocatalysis and visible-light photocatalysis. This new approach proceeds under ambient conditions and with excellent levels of regiocontrol. Mechanistic studies suggest that photoactivation of sydnones, rather than enamines, is key to the successful implementation of this process.
Synthesis of pyrazoles from 1,3-diols via hydrogen transfer catalysis
Schmitt, Daniel C.,Taylor, Alexandria P.,Flick, Andrew C.,Kyne, Robert E.
supporting information, p. 1405 - 1408 (2015/03/30)
1,3-Diols engage in ruthenium-catalyzed hydrogen transfer in the presence of alkyl hydrazines to provide 1,4-disubstituted pyrazoles. Regioselective synthesis of unsymmetrical pyrazoles from β-hydroxy ketones is also described.
