Wang et al. 167  described the development of selective and reversible SARS‐CoV‐1 Mpro inhibitors derived from HIV proteases inhibitors (Figure 25). The compound 85 as a SARS‐CoV‐1 Mpro lead inhibitor was continuously modified to obtain 86 and 87. These derivatives were highly selective toward SARS‐CoV‐1 Mpro versus HIV protease. Docking studies of 87 to Mpro demonstrated that both indole amino hydrogens establish H‐bond networks with side chain His142 and His41.