Polycyclic Orthoamides by Passerini-3CR

2 Polycyclic Systems via l-MCR and Intramolecular Diels-Alder Cycloaddition 

The first example of a tandem Ugi-4CR/intramolecular Diels-Alder reaction was reported by Paulvannan at Affimax [95], who obtained precursors for intramolecular Diels-Alder cycloadditions by an Ugi-4CR between furan-2-carboxaldehydes, monoamides or monoesters of fumaric or maleic acids, benzylamine, and benzyl isocyanide. The Ugi-4CR adducts 172 were never isolated since they underwent 

The same group reported that substrates having appendages that pre-encode 

Paulvannan has reported an efficient approach to rigid tricyclic nitrogen heterocycles via sequential and tandem Ugi-4CR/intramolecular Diels-Alder cydoaddi-tion of pyrrole derivatives. The Ugi-4CR was used to prepare trienes 187 from maleic and benzylmaleamic acids, which on heating at 60-120 °C for 12 h yielded 

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