Stereoselective Total Synthesis of Enantiomerically Pure 1-Trifluoromethyl Tetrahydroisoquinoline Alkaloids

Enantiomerically pure 1-trifluoromethyl-tetrahydroisoquinoline alkaloid analogues, in which C-1 is a quaternary stereogenic centre, have been synthesized by stereoselective intramolecular Pictet-Spengler reaction of the N-arylethyl γ-trifluoro-β-iminosulfoxide (R)-3, and subsequent elaborations of the sulfinyl auxiliary. The absolute stereochemistry of the stereogenic centre was determined by X-ray diffraction on the α-phenylpropionic ester (1R,2′S)-10.