Computational Study on the Acidic Constants of Chiral Brønsted Acids in Dimethyl Sulfoxide

The pK_a values of a series of chiral Brønsted acids, including N-triflylphosphoramides, bis­(sulfonyl)­imides, bis­(sulfuryl)­imides, dicarboxylic acids, sulfonic acids, and N-phosphinyl phosphoramides, were predicted by using the SMD/M06-2x/6-311++G­(2df,2p)//B3LYP/6-31+G­(d) method in DMSO. The results revealed that the calculated pK_a values ranged from −9.06 to 12.18 for different types of acids. The influence of acidic strength on reactivity and stereoselectivity was discussed using the calculated acidity data. Given that the choice of catalyst with appropriate acidity is the primary condition, several new catalyst candidates were designed by calculating corresponding pK_a values of parent acids.