posted on 2020-08-26, 09:13authored byRodrigo
A. Cormanich, Lucas A. Zeoly, Hugo Santos, Nilton S. Camilo, Michael Bühl, Fernando Coelho
In this work, the stereoselective
heterogeneous hydrogenation of
a tetrasubstituted indolizine was studied. Partial hydrogenation products
were obtained in three steps from a substituted pyridine-2-carboxaldehyde
prepared from commercial pyridoxine hydrochloride. The hydrogenation
of the indolizine ring was shown to be diastereoselective, forming trans-6b and cis-9. Theoretical calculations (ab initio and DFT) were
used to rationalize the unusual trans stereoselectivity
for 6b, and a keto–enol tautomerism under kinetic
control has been proposed as the source of diastereoselectivity.