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Updated: Oct 14, 2025

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Pd(II)-Catalyzed Enantioselective Ring-Contraction for the Construction of 1,4-Benzoxazines
Chenghao Ye1, Feng Gao1, Haipeng Wei1
1Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
Abstract:
Enantioselective ring-contraction reactions have not been widely reported. We have developed an enantioselective ring contraction of 5,6-dihydro-2H-benzo[b][1,4]oxazocines, affording enantiomerically enriched 3,4-dihydro-2H-1,4-benzoxazine derivatives as single regioisomers. An acidic additive is necessary in order to obtain the products with good yields and enantiomeric ratios (up to 93% yield, 98:2 er). The reaction was successfully performed on a gram scale, and the products can be derivatized easily.
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