Highly regioselective and metal-free gamma-addition of beta-keto esters to isatins, catalyzed by DABCO: direct access to novel class of diversely functionalized 3-hydroxy-2-oxindole scaffolds

作者：Thakur Pramod Bhagwan; Sirisha Katukuri; Sarma Akella Venkata Subrahmanya; Nanubolu Jagadeesh Babu; Meshram Harshadas Mitaram^*

来源：Tetrahedron, 2013, 69(31): 6415-6423.

DOI：10.1016/j.tet.2013.05.101

• Metal-free reaction
• Regioselective aldol reaction
• 3-Hydroxy-2-oxindole
• DABCO
• Green synthesis

DABCO catalyzed, highly regioselective gamma-addition of beta-keto esters has been achieved in the aldol reaction with isatins to afford gamma-(3-hydroxy-2-oxindole)-beta-keto ester structural framework under metal-free condition. The generality of the method has been demonstrated by screening series of isatin electrophiles as well as linear and cyclic beta-keto esters. Compare to the dianion method, the present method is very simple and handy, which provides straightforward access for the new diversely functionalized 3-beta-keto ester substituted-3-hydroxy-2-oxindole structural scaffolds in very good yields from readily available starting materials.

• 出版日期2013-8-5