oxazoline palladacyclic (COP) complex 4 containing acetate as a bridging ligand is an excellent catalyst for asymmetric intramolecular aminopalladation to synthesize 4-vinyloxazolidin-2-ones in 91−98% ee. In contrast to previously reported Pd(II) catalysts, COP-OAc (4) promotes the asymmetric cyclization of (Z)-allylic N-tosylcarbamates without prior activation by silver salts.
含
乙酸盐作为桥连
配体的
恶唑啉四环
钴(
COP)络合物4是出色的催化剂,可用于不对称分子内
氨基palpalation合成91-98%ee中的4-
乙烯基恶唑烷
丁二酮。与以前报道的Pd(II)催化剂相反,
COP-OAc(4)促进了(Z)-烯丙基N-
甲苯磺酰胺的不对称环化反应,而无需事先被
银盐活化。