Synthesis 2015; 47(05): 647-652
DOI: 10.1055/s-0034-1378682
© Georg Thieme Verlag Stuttgart · New York

Synthesis of 2,7-Diazabicyclo[2.2.1]heptenes by N–O Bond Cleavage of Arylnitroso Diels–Alder 1,2-Dihydropyridine Cycloadducts

Francesco Berti
Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy   Email:
Valeria Di Bussolo
Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy   Email:
Mauro Pineschi*
Dipartimento di Farmacia, Università di Pisa, Via Bonanno 33, 56126 Pisa, Italy   Email:
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Further Information

Publication History

Received: 10 September 2014

Accepted after revision: 17 November 2014

Publication Date:
09 December 2014 (online)


The cleavage of the N–O bond of nitrosoarene-derived cycloadducts with 1,2-dihydropyridines gives different products depending on the protecting group of the starting dihydropyridine and reaction conditions. The use of catalytic amounts of CuCl in non-nucleophilic solvents in combination with a N-phenoxycarbonyl-protected nitrosophenyl-derived cycloadduct allowed the unprecedented formation of the 2,7-diazabicycle[2.2.1]heptene scaffold. It was also demonstrated that this novel bicyclic gem-diamine derivative is an isolable intermediate en route to pyrrole derivatives. On the other hand, the corresponding nitrosopyridine-derived cycloadduct showed to be unreactive with copper salts, but the application of different reductive conditions can deliver the corresponding bicyclic gem-diamine derivative or 3-aminotetrahydropyridine also in enantioenriched form.

Supporting Information

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