Enantiopure binaphthyl azocines can be prepared in a single step via the direct copper-catalyzed reaction of binaphthyl azepines and α-diazo carbonyl reagents. The [1,2]-Stevens rearrangement is general (61–93% yields) and can be extended to [3]ferrocenophanes; similar reactivity in favor of the products of ring expansion is obtained with these ferrocene derivatives (80–96% yields).
Key words
azepine - azocine - diazo ester - ferrocenophane - [1,2]-Stevens rearrangement