entry ligand base solvent yield (%) ee (%)
1 L1 TMP toluene 83 14
2 L2 TMP toluene 58 78
3 L3 TMP toluene 67 68
4 L4 TMP toluene 70 13
5 L5 TMP toluene 26 13
6 L6 TMP toluene 7 3
7 L7 TMP toluene 52 2
8 L8 TMP toluene 72 21
9 L9 TMP toluene 62 69
10 L2 K2CO3 toluene 75 83
11 L2 DBU toluene 77 39
12 L2 K2CO3 DCE 78 89
13 L2 K2CO3 Ph-CF3 72 87