Arylglyoxal Monohydrate Based Multi-component Synthesis Of Aza-heterocycles Under Microwave Irradiation

The discourse includes four parts.The first section describes the application of microwave technology in thesynthesis of heterocyclic compounds as well as the application of multi-componentreactions and the reaction of phenylglyoxal hydrate participated research status, thesignificance and base of the selection of the subject, the original points and the researchtechniques.The second part describes microwave-assisted three-component domino reactionsof phenylglyoxal hydrate, enaminone and aromatic amines.(1) A new three-componentdomino reaction promoted by HOAc has been established, which provided divergentapproaches to multi-functionalized fused pyrroles with different substituted patterns.The direct intermolecular allylic amination and N-arylation of amines were achieved byvarying N-amino acid enaminones.(2) When p-TsOH, instead of HOAc, was used as apromoter, the reaction underwent another direction to give3-arylamino substitutedfused pyrrole derivatives. This reaction process involved in N-arylation-based domino[3+2] heterocyclization. This chemistry provides an efficient and promising syntheticstrategy to construction of the3-arylamino fused pyrrole skeleton.The third section describes the phenylglyoxal hydrate,N-aryl-5,5-dimethyl-cyclohex-2-enone and amino acids as starting materials in EtOHunder microwave irradiation, and a series of new oxazoloindolec derivatives with highyields were synthesized. Up to two new rings, five sigma bonds as well as three chairlcenter was achieved in this reaction; and N-substituted amine acids with high stereo-and diastereoselectivity were prepared. Further investigations are in progress in ourlaboratory to evaluate the process with a broader range of substrates, and to synthesizemore complex products and test their biological activity.The fourth part develops a novel domino reaction of phenylglyoxal hydrate2-(3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile and thiophenol undermicrowave irradiation. The efficient methodology for the synthesis of new and highlyfunctionalized2-azafluorenones via a three-component domino reaction involvingC1-aryl acylation, C3-thiolation, and C4-cyanation process has been presented. Thisdomino reaction enables successful assembly of three new sigma bonds including a C-Sbond and a C-N bond in a one-pot operation. Features of this strategy include the mildcondition, convenient one-pot operation, and short reaction periods. The structures of the products were determined by1H NMR, IR. Furthermore, thestructures of some products were confirmed X-ray analysis. And a possible reactionmechanism of each reaction was also supposed. The microwave-assisted reactionsmentioned above have advantages of shorter reaction time, higher yields and easierwork-up as well as environmentally friendly. Therefore, a new and environmentallyfriendly method for the synthesis of these important compounds is provided.