Exploiting Synergistic Catalysis for an Ambient Temperature Photocycloaddition to Pyrazoles
作者:Christopher P. Lakeland、David W. Watson、Joseph P. A. Harrity
DOI:10.1002/chem.201904210
日期:2020.1.2
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
Development of an Amine-Catalyzed Regioselective Synthesis of Pyrroles
作者:Taban K. K. Kakaawla、Joseph P. A. Harrity
DOI:10.1021/acs.orglett.7b03658
日期:2018.1.5
A regioselective synthesis of pyrroles has been devised through the cycloaddition of 1,3-oxazolium-5-olates and enamines. Product regiochemistry is controlled by the enamine substitution pattern. Moreover, an amine-catalyzed variant of this reaction allows aldehydes to be used directly as substrates for pyrrolesynthesis.