The first chiral isoxazoline ligands bearing spiro skeleton are developed. The spiro bis(isoxazoline) ligands (SPRIXs) are readily synthesized from diethyl malonate via double intramolecular nitrile oxide cycloaddition as a key step. The complex of (M, S, S)-R-SPRIX and Pd(OCOCF3)2 promoted the catalytic asymmetric Wacker-type cyclization of alkenyl alcohols to give optically active cyclic ethers for the first time. Furthermore, starting from dialkenyl alcohol, the enantioselective tandem cyclization via oxy-palladation was achieved with up to 95% ee. Asymmetric ligands other than SPRIKs promote neither the Wacker-type reaction nor the tandem reaction.
|Number of pages||11|
|Journal||Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry|
|Publication status||Published - 2004 Jan|
- Nitrile oxide cycloaddition
- Tandem reaction
ASJC Scopus subject areas
- Organic Chemistry