Answers are grounded in this paper and cite their sources.
The first highly diastereoselective Michael addition/condensation/Friedel-Crafts alkylation cascade reaction of 3-indolyl-substituted oxindoles with ortho-hydroxychalcones was established, which afforded a wide range of polycyclic indole-bridged chroman spirooxindoles with novel and complex scaffolds in moderate to excellent yields.
No takes yet. Share an insight, caveat, or question.
Guo et al. (2018) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: