In this research, one-pot synthesis of aliphatic pincer ligands via S_N2 reaction have been studied using theoretical calculations. The kinetics and thermodynamics of the reactions between dialkylhalophosphines and bis(2-haloethyl)amines have been studied and compared with the experimentally successful one-pot synthesis of arene-based PCP/PNP pincer ligands. The effect of the leaving group, hetero atom, solvent, and substitution have been investigated and it has been shown that the synthesis of aliphatic pincer ligands with iodophosphines and bis(2-iodoethyl)amine in the presence of acetonitrile as solvent have the lowest activation free energy (ΔG^≠) and highest reaction rate (k). Consequently, the calculations suggest the suitable condition for one-pot synthesis of aliphatic pincer ligands via the proposed S_N2 reaction