1.
J Org Chem
; 84(21): 13824-13831, 2019 11 01.
Artigo
em Inglês
| MEDLINE
| ID: mdl-31566387
RESUMO
A correlation between the equilibrium ratio of tautomeric products generated by the asymmetric Michael reactions of cyclic carbon acids with ß,γ-unsaturated α-keto esters and the chemical shift of the α-proton in starting nucleophilic substrates was revealed which makes equilibration predictable. New tetrahydropyran-fused benzo[a]phenazins were enantioselectively (up to 99% ee) synthesized from ß,γ-unsaturated α-keto esters and benzo[a]phenazin-5-ol, a powerful anti-cancer agent sAJM589. Facile recyclability of catalyst Ia in the catalytic reactions was demonstrated.