An efficient asymmetric aerobic oxidation of tetrahydroisoquinolines with terminal alkynes was realized under mild reaction conditions using O2 as the sole oxidant. A chiral N,N′-dioxide/zinc(II)/iron(II) bimetallic cooperative catalytic system proves to be efficient for the formation of various α-alkynyl substituted tetrahydroisoquinolines in good to excellent yields and enantioselectivities. A primary
Catalytic Asymmetric Alkynylation of C1-Substituted C,N-Cyclic Azomethine Imines by CuI/Chiral Brønsted Acid Co-Catalyst
作者:Takuya Hashimoto、Masato Omote、Keiji Maruoka
DOI:10.1002/anie.201104017
日期:2011.9.12
up: The title reaction was developed for the synthesis of chiral tetrahydroisoquinoline derivatives with a tetrasubstituted carbon center at the C1‐position (see scheme, Bz=benzoyl, pybox=2,6‐bis(2‐oxazolinyl)pyridine). The reaction was facilitated effectively by the co‐catalyst system composed of copper(I)/Ph‐pybox and an axiallychiraldicarboxylicacid.