Domino reactions. The green and economical art of chemical synthesis

The efficient synthesis of natural products, drugs, agrochemicals and materials is a very important aspect in academia and industry. To allow an ecologically and economically favourable approach in a green fashion the former stepwise procedures must be replaced by domino reactions which allow the preparation of complex molecules starting from simple substrates in a straight forward way. Domino reactions1 allow the reduction of the amount of waste being formed and the preservation of our resources. Moreover, they are also favourable in an economical way since they consume less time and less material.

The usefulness of the domino concept[1] is demonstrated with the syntheses of some fungal metabolites as blennolide A[2] and secalonic acid E[3] with a dimeric tetrahydroxanthenone skeleton using an enantioselective domino-Wacker/carbonylation/methoxylation reaction and of the natural aryldihydronaphthalene lignan linoxepine[4] employing a domino-carbopalladation/Heck reaction. The approach has also been applied for the synthesis of novel materials such as molecular switches[5a-e] and fluorescence dyes[6a,b] using a domino-Sonogashira/ carbopalladation/CH-activation reaction.