Synergistic   Promotion by Intramolecular Hydrogenbonding: a Bi-functionally Catalyzed   Cascade Reaction for the Synthesis of Enantiopure Chromenopyrrolidines

Jian Cao, Jin-Yu   Liu, Yi-Ming Zhang, Zhu-Yin Wang and Peng-Fei Xu*

https://doi.org/10.1039/C8QO01208C