An Unexpected Oxidative C-O Bond Formation: 11,17a-Dihydrobenzo[4,5]oxazolo[3,2-A]dinaphtho[2,1- C:1',2'-E]azepine

Phosphoric acids bound to 3,3’-subsituted 1,1’-binaphthalene-2,2’-diol (BINOL) have found wide application as effective asymmetric catalysts. In this work, we describe our attempt to construct a new binaphthalene-based phosphoric acid 6. We found that both the key precursor 2 and the desired product 6 decay rapidly and quantitatively to a stable dihydrooxazole 3 via an O₂-driven oxidative C-O bond formation.