Development of a Mild Procedure for the Addition of Bisulfite to Electrophilic Olefins
作者:Francesco Fini、Murali Nagabelli、Mauro F. A. Adamo
DOI:10.1002/adsc.201000543
日期:2010.12.17
The sulfonylation of activated alkenes is an important yet unexplored reaction due to the harshness of conditions required. We have identified a procedure which allowed the reaction of alkenes with equimolar amounts of bisulfite at room temperature.
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 Fast and Highly Efficient Protocol for Synthesis of Pyrrolo[2,3-d]isoxazoles and a New Series of Novel Benzyl Bis-pyrrolo[2,3-d]isoxazoles Using Task-Specific Ionic Liquids as Catalyst and Green Solvent
We report a mild, fast, highly efficient and eco-friendly protocol for the green synthesis of pyrrolo[2,3-d]isoxazoles and a new series of novel benzyl bis-pyrrolo[2,3-d]isoxazoles from nitro styrylisoxazoles in SnCl(2)-ionic liquid by reductive cyclization. These reactions were performed at ambient temperature which resulted in good yields in short reaction time, without requiring any organic solvent
Michael addition of acetylacetone to 3-methyl-4-nitro-5-(o-hydroxystyryl)isoxazoles gives 4-(o-acetoxyphenyl)-5-(3-methyl-4-nitro-5-isoxazolyl)-2-pentanones (4). Reductive cyclization of 4 with tin(II) chloride and concentrated hydrochloric acid leads to 7-(o-hydroxyphenyl)-3,5-dimethyl-7,8-dihydro-6H-isoxazolo[4,5-b]azepines. The formation of 4 has been rationalized through ortho effect. NMR and mass spectra of products have been discussed.
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.