Synthesis of 2-hydroxy-3-indolinones and 3-hydroxy-2-indolinones by anionic cyclization, in situ oxidation and rearrangement
摘要:
Lithiation with butyllithium of 2-(benzylamino)benzamides (N-benzyl anthranilamides) occurs at the benzylic position to give an alpha-amino-organolithium that cyclizes to the 3-indolinone (indoxyl) ring (similar to a Parham cyclization). Autoxidation in air gives 2-hydroxy-3-indolinones. In the absence of a proton source, rearrangement of the aryl group from C-2 to C-3 occurs to give the 3-hydroxy-2-indolinone (oxindole) ring. (C) 2010 Elsevier Ltd. All rights reserved.
proline was designed and synthesized as a bifunctional organocatalyst for the “on-water” asymmetric Michael addition of less-hydrophobic oxoindoles to nitroolefins. Employing only 1 mol% of this bifunctional organocatalyst demonstrated exceptional catalytic efficiency (>90 % yield in most cases) and stereoselectivity in reactions involving various 3-substituted oxoindoles (up to > 99 % de and 96 % ee) and
设计并合成了由脯氨酸衍生的二氯苯基取代的手性脲,作为双功能有机催化剂,用于疏水性较低的氧代吲哚与硝基烯烃的“水上”不对称迈克尔加成。仅使用 1 mol% 的这种双功能有机催化剂,在涉及各种 3-取代氧代吲哚(高达 > 99% de 和 96% ee)和硝基烯烃(高达 > 99% de 和 98% ee)。