An efficient solvent-free synthesis of 3-methyl-4-nitro-5-styrylisoxazoles using solid nano-titania
作者:Kartikey Dhar Dwivedi、Sameer Reddy Marri、Satish Kumar Nandigama、Raju L Chowhan
DOI:10.1007/s12039-018-1534-0
日期:2018.9
sustainability of the catalyst was tested by performing recyclability experiment up to 4 cycles. Calculated turn over frequency (TOF) for each cycle indicates the protocol as sustainable. Graphical Abstract: SYNOPSISAn efficient and solvent-free procedure for the synthesis of 3-methyl-4-nitro-5-styrylisoxazoles using nano-titania as solid support and recyclablecatalyst is presented. This method provides a useful
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.
A strategy for the N-heterocycliccarbene (NHC) catalyzed asymmetric synthesis of 3,5-diaryl substituted cyclohexenones has been developed via oxidative [4+2] annulation of enals and alkenylisoxazoles. It is the first example of using NHC organocatalysis in a double vinylogous Michael type reaction, a challenging but highly desirable topic. This unprecedented protocol affords good yields as well as
A wide range of structurally diverse 3,3′-thiopyrrolidonyl spirooxindoles bearing three contiguous stereogenic centers can be smoothly obtained via a domino Michael/cyclization reaction between 3-isothiocyanato oxindoles and 3-methyl-4-nitro-5-alkenyl-isoxazoles with commercially available quinine as the catalyst under mild conditions. The protocol is significantly characterized by high reactivity
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.