Enantioselective Synthesis of 1‑Aryl Tetrahydroisoquinolines by the Rhodium-Catalyzed Reaction of 3,4-Dihydroisoquinolinium Tetraarylborates
journal contributionposted on 25.01.2021, 20:44 by Wei-Sian Li, Ting-Shen Kuo, Ping-Yu Wu, Chien-Tien Chen, Hsyueh-Liang Wu
The 1-aryl tetrahydroisoquinolines (1-aryl THIQs) are omnipresent in biologically active molecules. Here we report on the direct asymmetric synthesis of these valuable compounds via the reaction of 3,4-dihydroisoquinolinium tetraarylborates. The dual roles of anionic tetraarylborates, which function as both prenucleophiles and stabilizers of 3,4-dihydroisoquinolinium cations, enable this rhodium(I)-catalyzed protocol to convergently provide enantioenriched 1-aryl THIQs in good yields (≤95%) with ≤97% ee, as demonstrated by the formal synthesis of (−)-solifenacin and the facile synthesis of (−)-Cryptostyline I.