Asymmetric Synthesis of Imidazo[2,1‐a]isoquinolin‐3‐ones with Dihydroisoquinolines and N‐substituted Amino Acids

Abstract A mild direct synthesis of chiral imidazo[2,1‐ a ]isoquinolin‐3‐one derivatives with dihydroisoquinolines and N ‐substituted amino acids have been developed. By the use of easily accessible DCC as condensation reagent at ambient temperature, a series of imidazo[2,1‐ a ]isoquinolin‐3‐ones can be assembled readily in low to good yields with low to excellent dr values. Interestingly, the use of N ‐substituted L ‐Threonine and L ‐Serine afforded oxazino[2,3‐ a ]isoquinolin‐4‐one derivatives with good diastereoselectivities.