CHEMISTRYSELECT, cilt.9, ss.1-10, 2024 (SCI-Expanded)
Spirocyclic compounds have always attracted attention due to
their presence as a structural core in a wide variety of natural
and bioactive molecules and to exhibit pharmaceutical properties. An asymmetric synthesis of spiro[indoline-3,4’-pyrano[2,3-
c]pyrazoles] via Michael addition of trifluoromethyl substituted
pyrazolone to isatylidene ethyl cyanoacetate derivatives was
conducted with excellent enantioselectivities up to 99% and up
to 97% isolated yield at room temperature with using 2 mol%
of bifunctional quinine derived squaramide organocatalysts.