One-pot synthesis of functionalized isoxazole–thiolane hybrids via Knoevenagel condensation and domino sulfa-1,6-Michael/intramolecular vinylogous Henry reactions
Catalyst‐free synthesis of the isoxazole‐spirooxindole‐tetrahydrothiophene hybrids is reported. Formation of 1,4‐thia‐Michael and intramolecular aldol reactions were observed (instead of 1,6‐thia‐Michael followed by vinylogous Henry reactions) in a regioselective fashion to give new isoxazole‐spirooxindole‐tetrahydrothiophene hybrids with excellent yields.
Organocatalyzed asymmetric vinylogous Michael addition of α,β-unsaturated γ-butyrolactam
作者:Jinlong Zhang、Xihong Liu、Xiaojuan Ma、Rui Wang
DOI:10.1039/c3cc44059a
日期:——
Highly efficient asymmetric vinylogous 1,6-Michael addition of α,β-unsaturated γ-butyrolactam to 3-methyl-4-nitro-5-alkenyl-isoxazoles and Michael addition to trichloromethyl ketones by using a chiral quinine-derived squaramide organocatalyst were described, giving products with high diastereo- and enantioselectivities (up to >25â:â1 dr and 96% ee).
One-pot synthesis of functionalized isoxazole–thiolane hybrids via Knoevenagel condensation and domino sulfa-1,6-Michael/intramolecular vinylogous Henry reactions
作者:Sakkani Nagaraju、Neeli Satyanarayana、Banoth Paplal、Anuji K. Vasu、Sriram Kanvah、Balasubramanian Sridhar、Prabhakar Sripadi、Dhurke Kashinath
DOI:10.1039/c5ra16721c
日期:——
One-pot synthesis of isoxazole–thiolane hybrids are reported via the Knoevenagel condensation, domino sulfa-1,6-Michael/intramolecular vinylogous Henry reactions using piperidine (30 mol%) with >95% yields in 2–2.5 h overall reaction time.