Synthesis of spirobarbiturate-pyrrolidinones: Via a domino aza-Michael/SN2 cyclization of barbiturate-derived alkenes with N-alkoxy α-haloamides
A highly efficient domino aza-MIRC (Michael Induced Ring Closure) reaction between barbiturate-derived alkenes and N-alkoxy α-haloamides has been achieved in moderate to excellent yields. This reaction proceeds smoothly under mild conditions via a domino aza-Michael addition/intramolecular SN2 sequence, providing a practical tool in the synthesis of bioactive molecules spirobarbiturate-3-pyrrolidinones.
2-Phenyl-2,3-dihydrobenzo[ d ]thiazole: A Mild, Efficient, and Highly Active in situ Generated Chemoselective Reducing Agent for the One-Pot Synthesis of 5-Monoalkylbarbiturates in Water
A metal- and catalyst-free reductive alkylation protocol for the one-pot synthesis of 5-monoalkylbarbiturates from barbituric acids and aldehydes using the in situ generated chemoselective reducing agent 2-phenyl-2,3-dihydrobenzo[ d ]thiazole from 2-aminothiophenol and benzaldehyde is described. The notable advantages of the protocol are operational simplicity, mild reaction conditions, high yield, short reaction time, and simple workup and purification process which make it highly attractive.
Kalita, Subarna Jyoti,Deka, Dibakar Chandra
p. 477 - 482
(2017/12/06)
“On-water” catalyst-free, one-pot synthesis of quaternary centered and spiro-tetrahydrothiophene-barbiturate hybrids
A green and efficient method have been developed for the synthesis of quaternary centered and spiro-barbiturate-tetrahydrothiophene hybrids via Knoevenagel condensation,1,4-thia-Michael and intramolecular Aldol reactions using “on water” concept under catalyst-free conditions. Systematic studies were carried out to find the role of the water and total reaction concentration (0.086?M) to promote the reaction in two steps (one-pot). The use of water as a reaction medium, catalyst-free conditions, broad substrate scope, one-pot approach for the creation of quaternary centered and spiro molecules are the advantages of this method.
Asymmetric Construction of Highly Functionalized Spirobarbiturate-Cyclopentenes through Chiral Phosphine-Catalyzed [3+2] Annulation of Morita–Baylis–Hillman Carbonates with Barbiturate-Derived Alkenes
A multifunctional chiral phosphine-catalyzed enantioselective [3+2] annulation of Morita–Baylis–Hillman carbonates with barbiturate-derived alkenes has been achieved under mild conditions, providing a variety of chiral spirobarbiturate-cyclopentenes in moderate to excellent yields with moderate to excellent diastereo- and enantioselectivities. (Figure presented.).