Diethyl oxomalonate as a three carbon synthon for synthesis of functionalized 1,1′-disubstituted tetrahydroisoquinoline

Pictet–Spengler condensation of β-arylethylamine with diethyl oxomalonate provides an entry to highly functionalized 1,1′-disubstituted tetrahydroisoquinoline in high yield. Selective functionalization of two ester groups is demonstrated. Syntheses and functional group transformations of 1,1-disubstituted tetrahydroisoquinoline are reported.