Organocatalytic tandem enantioselective Michael-cyclization of isatin-derived β,γ-unsaturated α-ketoesters with 3-hydroxy-4H-chromen-4-one or 2-hydroxy-1,4-naphthoquinone derivatives

Shao-Jie Yin,^aShao-Yun Zhang,^aJun-Qi Zhang,^aBing-Bing Sun,^aWei-Tai Fan,^aBing Wu^aand Xing-Wang Wang*^a（王兴旺）

^aKey Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P. R. China

RSC Adv.,2016,6, 84248-84254

The enantioselective formal [3 + 3] annulation reaction of isatin-derived β,γ-unsaturated α-ketoesters with 3-hydroxy-4H-chromen-4-ones or 2-hydroxy-1,4-naphthoquinone was successfully implemented under catalysis of quinine-derived bifunctional tertiary amine-thiourea catalysts. The efficient tandem Michael-cyclization has provided facile access to optically active spiro[oxindole-pyrano[3,2-b]chromenone] and spiro[oxindole-benzo[g]chromene-dione] derivatives in high yields with excellent diastereo- and enantioselectivities.

链接：http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra17400k#!divAbstract