A one pot domino protocol for an efficient synthesis of 7-arylbenzo[c]acridine-5,6-diones, with a novel nucleus, has been developed by reacting 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes and aromatic amines using environmentally benevolent p-toluene sulphonic acid as a catalyst. An exciting feature of this communication is the reaction mechanism that depends on the reaction solvent.

(Z)-2-Enynyl-2-hydroxy-imidazolidine-4,5-diones 2 are synthesized for the first time via Cu(I)-mediated (Z)-selective geminal coupling among two molecules of terminal alkynes, carbodiimides, and oxalyl chloride. Further transformation of 2a is performed to yield a highly functionalized spiro heterocyclic compound 5.

A novel four-component bicyclization strategy has been established, allowing a flexible and practical approach to 37 examples of multicyclic pyrazolo[3,4-b]pyridines from low-cost and readily accessible arylglyoxals, pyrazol-5-amines, aromatic amines, 4-hydroxy-6-methyl-2H-pyran-2-one, and cyclohexane-1,3-diones. The polysubstituted cyclopenta[d]pyrazolo[3,4-b]pyridines were stereoselectively s...

A facile, efficient, single-step protocol for the synthesis of difluoromethyl enol ether derivatives by O-difluoromethylation of 1,3-diones via in situ generation of difluorocarbene from ClCF2CO2Et has been developed. The functional group tolerance, scalability of the reaction, and mild reaction conditions make it an attractive protocol for the synthesis of biologically relevant difluoromethyl ...

An efficient and regioselective procedure for the synthesis of di-, tri- and fully-substituted pyrazolidine-3,5-diones on a solid-phase format is described. Microwave irradiation provided significant rate enhancement in this protocol. To demonstrate the versatility of this chemistry, a representative set of 25 compounds was prepared.

A series of 4-aryl-6-methyl-3,4-dihydro-2H-pyrano[3,2-c]quinolin-2,5(6H)-diones were synthesized via the three-component reactions of aromatic aldehydes, 4-hydroxy-1-methylquinolin-2(1H)-one, and Meldrum's acid catalyzed by L-proline. The structures of the products were identified by spectroscopic analysis. A mechanism for this three-component reaction catalyzed by L-proline was proposed.

We discovered a novel organocatalysed multicomponent domino Knoevenagel-aza-Michael-cyclocondensation reaction leading to an unprecedented straightforward synthesis of 1,5-diazabicyclo[3.3.0]octane-2,6-diones. The specific capability of the (DHQ)2PHAL organocatalyst in this process was also highlighted to eventually furnish the corresponding bicyclopyrazolidinones with up to 96 : 4 er.

A novel and efficient cascade annulation of tertiary α-hydroxy ketones and dimethyl but-2-ynedioate is reported. The reaction, which only requires a base as the promoter, provides a straightforward access to polysubstituted pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones under very mild reaction conditions.