Optically active diaryl tetrahydro-isoquinoline derivatives

Abstract

In (1R,3S)-6,7-dimeth-oxy-3-(meth-oxy-diphenyl-methyl)-1-phenyl-1,2,3,4- tetra-hydro-isoquinoline, C 31H 31NO 3, (I), and (1R,3S)-2-benzyl-3-[diphenyl(trimethyl-siloxy)methyl]-6,7-dimeth-oxy-1-phenyl-1, 2,3,4-tetra-hydro-isoquinoline, C 40H 43NO 3Si, (II), the absolute configurations have been confirmed to be R and S at the isoquinoline 1- and 3-positions, respectively, by NMR spectroscopy experiments. Both structures have monoclinic (P2 1) symmetry and the N-containing six-membered ring assumes a half-chair conformation. The asymmetric unit of (I) contains one mol-ecule, while (II) has two mol-ecules within the asymmetric unit. These structures are of inter-est with respect to the conformation around the exocyclic C - C bond: (I) displays an ap (anti-periplanar) conformation, while (II) displays an sc-exo (synclinal) conformation around this bond. These conformations are significant for stereocontrol when these compounds are used as catalysts. Various C - H⋯π and C - H⋯O bonds link the mol-ecules together in the crystal structure of (I). In the crystal structure of (II), three inter-molecular C - H⋯π hydrogen bonds help to establish the packing. © 2011 International Union of Crystallography.