Fig. 2: Optimization of chiral Brønsted acid catalyst structures.
From: Bis-indole chiral architectures for asymmetric catalysis
The reaction of 1a (0.1 mmol), acetone (0.5 mmol), and stated amount of catalysts was carried out in 0.5 ml of toluene in a 4 mL heavy wall vessel. The vessel was sealed and stirred at the stated temperature for 3 days (more details see Supplementary Figs. S1–S5). Isolated yields are shown. The ee values were determined by chiral SFC analysis.
