Abstract
The transfer hydrogenation reaction of (1,2,3)triaz olo(1,5-a)pyridines with Pd/C/Zn or Pd(OH) 2/C/Zn in water, ethanol or water/ethanol mixture ha s been explored. 4,5,6,7-Tetrahydro- triazolopyridines were obtained in good to medium yields. In addition, under the same conditions 2-substituted pyridines were also formed as a resul t of intermediate pyridylcarbene formation, by triazole ring opening and loss of nitrogen.
Highlights
Hydrogenation of organic molecules under homogeneous[2,3] or heterogeneous[4,5] catalysis is a process very widely used in industrial synthetic organic chemistry
We report here the chemistry of [1,2,3]triazolo[1,5-a]pyridines with Pd/Zn mixtures in the presence of hydrogen donors
We performed reactions under similar conditions to those previously used with quinolines,[24] with different triazolopyridines 4, Zn powder, Pd/C catalyst and H2O, H2O/EtOH or EtOH, as solvents and as hydrogen donors, in an autoclave at 150 oC over 24 hours (Scheme 2)
Summary
Hydrogenation of organic molecules under homogeneous[2,3] or heterogeneous[4,5] catalysis is a process very widely used in industrial synthetic organic chemistry. We performed reactions under similar conditions to those previously used with quinolines,[24] with different triazolopyridines 4, Zn powder, Pd/C catalyst and H2O, H2O/EtOH or EtOH, as solvents and as hydrogen donors, in an autoclave at 150 oC over 24 hours (Scheme 2). When the reaction was performed with triazolopyridine 4a (Table 1, entries 1-3), transfer hydrogenation took place and 3-phenyl-4,5,6,7-tetrahydrotriazolopyridine 5a was obtained, in low yield.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
