Spiro cyclohexanone-oxindole

Lan, Y.-B., Zhao, H., Liu, Z.-M., Liu, G.-G., Tao, J.-C., Wang, X.-W. (2011). Chiral counteranion synergistic organocatalysis under high temperature efficient construction of optically pure spiro[cyclohexanone-oxindole] backbone. Organic Letters, 13,4866-4869. 

In 2011 Lan et al. [48] reported an efficient construction of the spiro[cyclohexanone-oxindole] backbone catalyzed by a combination of a chiral cinchona-based primary amine and (R)-BINOL-phosphoric add. It was found that the reaction proceeded much faster with the elevation of temperature from room temperature to 80 C, without affecting either the diastereoselectivities or enantioselectivities (Scheme 21.20). 

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