An efficient modular stereoselective synthesis of highly functionalized tetrahydroisoquinolines and C2
-1,1′-bitetrahydroisoquinolines chiral ligands is disclosed. The synthetic methodology relies on direct stereoselective Pictet–Spengler cyclization between (S)-4-benzyloxazolidin-2-ones and various mono- and dialdehydes using inexpensive sulfuric acid as the catalyst.
Key words
stereoselective synthesis - chiral bitetrahydroisoquinolines -
C
2-symmetric chiral ligands - diastereoselective Pictet–Spengler reaction - isoquinoline