Highly efficient hydrogen-bonding catalysis of the Diels-Alder reaction of 3-vinylindoles and methyleneindolinones provides carbazolespirooxindole skeletons

Carbazolespirooxindole derivatives were synthesized in a high-yielding, atypically rapid, stereocontrolled Diels-Alder reaction catalyzed by a C(2)-symmetric bisthiourea organocatalyst. Simple precursors and mild conditions were used to construct carbazolespirooxindole derivatives with high enantiopurity and structural diversity under H-bonding catalysis. The practical approach recycles the organocatalyst and solvent. This simple and efficient operational procedure will allow diversity-oriented syntheses of this intriguing class of compounds.