A highly enantioselective synthesis of 3-amino-2-oxindoles by direct Mannich reaction between acetylacetone and N-carbamoyl isatin ketimine has been described herein. Corresponding chiral adducts were obtained in high yields (up to 98%) and with excellent enantioselectivities (up to >99% ee) by very low (1 mol%) catalyst loading of 2-adamantyl substituted bifunctional cinchona-squaramide.

中文翻译：

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乙酰丙酮和靛红衍生的酮亚胺的不对称有机催化直接曼尼希反应：手性金鸡纳-方酸酰胺中的催化剂负载量低

本文已经描述了通过乙酰丙酮和N-氨基甲酰基异丁酮酮亚胺之间的直接曼尼希反应进行的3-氨基-2-氧吲哚的高度对映选择性的合成。通过极低（1 mol％）2-金刚烷基取代的双官能金鸡纳-方酸酰胺的催化剂负载量，可以以高收率（最高98％）和出色的对映选择性（最高> 99％ee）获得相应的手性加合物。