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

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.

Automated summary

A mild direct synthesis of chiral imidazo[2,1-a]isoquinolin-3-one derivatives with dihydroisoquinolines and N-substituted amino acids has been developed. The use of easily accessible DCC as condensation reagent at ambient temperature allows for the assembly of a series of imidazo[2,1-a]isoquinolin-3-ones in low to good yields with low to excellent diastereomeric ratios. Interestingly, the use of N-substituted L-Threonine and L-Serine affords oxazino[2,3-a]isoquinolin-4-one derivatives with good diastereoselectivities.