Fig. 2: Enantioselectivity transition states of reaction 1 with 1a to 2a as example.

The forming of the S-configuration product 2a is the favored one (TS-S is favored over TS-R by 2.7 kcal/mol. Calculations at SMD(toluene)-M06L-D3/Def2TZVP//PBE-D3/Def2SVP/W06 level).