Background: We report a novel MCR4 useful for generating chiral analogs of staurosporine a promiscuous and potent protein kinases inhibitor.
Method: Our strategy introduces the use of substituted tetramic acids as chiral precursors which together with an aldehyde, an isocyanide, a dienophile and a Lewis acid lead to hexa-substituted benzenes in one pot.
Conclusion: Interestingly, the use of chiral precursors not only allowed obtaining a stereo- controlled reaction, but also observing unusual atropo-diastereomers with axial chirality. The reaction can be carried out both under thermal or microwave conditions. The methodology is demonstrated for a panel of aldehydes, tetramic acids, isocyanides and dienophiles.
Keywords: Staurosporine, multicomponent reaction, Ugi, isocyanide, tetramic acid, hexa-substituted benzene, Meldrum's acid.