[reaction: see text]. A novel, microwave-enhanced, highly efficient protocol for the synthesis of hitherto unknown (-)-steganacin and (-)-steganone 7-aza analogues containing a 1,2,3-triazole ring has been presented. Microwave irradiation was found to be highly beneficial in promoting the Suzuki reaction and the 1,3-dipolar cycloaddition reaction to generate the highly strained medium-sized ring system of the title molecules.

A novel microwave-assisted, highly efficient protocol for the synthesis of hitherto unknown aza-analogues of (-)-Steganacin, a naturally occurring bisbenzocyclooctadiene lignan lactone with potent antileukemic and tubulin polymerization inhibitory activity, has been developed. Focused microwave irradiation is demonstrated to be highly beneficial in promoting the three crucial steps of the sequence to effect the final ring closure: the Suzuki-Miyaura reaction, Cu-mediated A3-coupling, as well as the intramolecular Huisgen 1,3-dipolar cycloaddition.

No abstract

A high yield multicomponent reaction providing multifunctionalized pyrido[2,3-d]pyrimidines with up to four diversity centers in a one-pot microwave-assisted cyclocondensation of alpha,beta-unsaturated esters, amidine systems and malononitrile (or ethyl cyanoacetate) is described.