Overall, the substrates' activation in FC alkylation mechanism with SCP_Q111BpyAla favours the formation of proS product over proR while with SCP_Q111CBpy favours proR product formation over proS. However, the products distribution was achieved via a competitive pathway, so a mixture of both enantiomers of the product is predicted, which agrees well with our experimental results. The larger difference in the relative energies for the SCP_Q111BpyAla TS intermediates matches the experimental observation of improved enantioselectivity when using SCP_Q111BpyAla as the catalyst over the use of SCP_Q111CBpy