A facile three-component [3+2]-cycloaddition/annulation domino protocol for the regio- and diastereoselective synthesis of novel penta- and hexacyclic cage systems, involving the generation of two heterocyclic rings and five contiguous stereocenters

Catalyst-free synthesis of acenaphthoindolopyrimidine derivatives

A one pot three component reaction of acenaphthoquinone, barbituric acid/thiobarbituric acid/N,N-dimethyl barbituric acid and arylamines in ethanol for the synthesis of acenaphthoindolopyrimidine derivatives is reported. The reactions take place without a catalyst and gentle conditions. This method is facile and has some benefits such as, readily available starting materials, green solvent, catalyst-free, no column chromatographic purification and good to high yields.

Azomethine Ylides-Versatile Synthons for Pyrrolidinyl-Heterocyclic Compounds

Azomethine ylides are nitrogen-based three-atom components commonly used in [3+2]-cycloaddition reactions with various unsaturated 2π-electron components. These reactions are highly regio- and stereoselective and have attracted the attention of organic chemists with respect to the construction of diverse heterocycles potentially bearing four new contiguous stereogenic centers. This review article complies the most important [3+2]-cycloaddition reactions of azomethine ylides with various olefinic, unsaturated 2π-electron components (acyclic, alicyclic, heterocyclic, and exocyclic ones) reported over the past two decades.

Synthesis of new spiro pyrrole/pyrrolizine/thiazole derivatives via (3+2) cycloaddition reactions

An efficient one-pot multi-component protocol has been developed for the synthesis of novel spiro-fused pyrrole/pyrrolizine/thiazole derivatives using (3+2) cycloaddition reactions; all products were obtained in moderate to excellent yields and synthesized from commercially available starting materials.

Synthesis of penta- and tetra-cyclic cage-like compounds and dispiro heterocycles through microwave-assisted solvent-free multi-component domino reactions

Novel penta- and tetra-cyclic cage-like compounds and dispiro heterocycles were obtained as a result of a microwave-assisted three-component domino reaction.

A Sustainable Approach to the Stereoselective Synthesis of Diazaheptacyclic Cage Systems Based on a Multicomponent Strategy in an Ionic Liquid

The microwave-assisted three-component reactions of 3,5-bis(E)-arylmethylidene]tetrahydro-4(1H)-pyridinones, acenaphthenequinone and cyclic α-amino acids in an ionic liquid, 1-butyl-3-methylimidazolium bromide, occurred through a domino sequence affording structurally intriguing diazaheptacyclic cage-like compounds in excellent yields.

Three-component access to 2-pyrrolin-5-ones and their use in target-oriented and diversity-oriented synthesis

The combination of two multicomponent reactions,i.e.a Hantzsch-type synthesis of 2-pyrrolin-5-ones and a 1,3-dipolar cycloaddition generated complex spirocyclic systems.

A catalyst-free multicomponent domino sequence for the diastereoselective synthesis of (E)-3-[2-arylcarbonyl-3-(arylamino)allyl]chromen-4-ones

The three-component domino reactions of (E)-3-(dimethylamino)-1-arylprop-2-en-1-ones, 3-formylchromone and anilines under catalyst-free conditions afforded a library of novel (E)-3-(2-arylcarbonyl-3-(arylamino)allyl)-4H-chromen-4-ones in good to excellent yields and in a diastereoselective transformation. This transformation generates one C–C and one C–N bond and presumably proceeds via a reaction sequence comprising a Michael-type addition–elimination reaction, a nucleophilic attack of an enamine to a carbonyl reminiscent of one of the steps of the Bayllis–Hilman condensation, and a final deoxygenation. The deoxygenation is assumed to be induced by carbon monoxide resulting from the thermal decomposition of the dimethylformamide solvent.

5-[(E)-4-Fluoro-benzyl-idene]-8-(4-fluoro-phen-yl)-2-hy-droxy-9-phenyl-3,10-diaza-hexa-cyclo-[10.7.1.1.0.0.0]henicosa-1(20),12,14,16,18-pentaen-6-one

In the title compound, C₃₈H₂₈F₂N₂O₂, the piperidine ring adopts a chair conformation and the pyrrolidine ring adopts an envelope conformation with the spiro C atom as the flap atom. The naphthalene ring system makes dihedral angles of 39.89 (8), 35.33 (8) and 46.45 (8)° with the two fluoro-substituted benzene rings and the phenyl ring, respectively, while the dihedral angle between the two fluoro-substituted benzene rings is 75.21 (10)°. An intra­molecular O—H⋯N hydrogen bond generates an S(5) ring. In the crystal, mol­ecules are connected by C—H⋯O hydrogen bonds, forming supra­molecular chains propagating along the c-axis direction. Weak C—H⋯π inter­actions further consolidate the structure.