Synthesis 2016; 48(12): 1855-1864
DOI: 10.1055/s-0035-1561423
special topic
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Substituted Pyrrolo[2,1-a]isoquinolines by Gold-Catalyzed Domino Cyclization of Alkynyl Iminoesters

Kenji Sugimoto
a   Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan   Email: matsuya@pha.u-toyama.ac.jp
,
Yuya Hoshiba
a   Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan   Email: matsuya@pha.u-toyama.ac.jp
,
Kiyoshi Tsuge
b   Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555, Japan
,
Yuji Matsuya*
a   Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan   Email: matsuya@pha.u-toyama.ac.jp
› Author Affiliations
Further Information

Publication History

Received: 28 January 2016

Accepted: 23 February 2016

Publication Date:
13 April 2016 (online)


Abstract

A novel gold-catalyzed double cyclization leading to a biologically important pyrroloisoquinoline skeleton was established. The reaction sequence involving 6-exo-dig cyclization of alkynyl iminoester and [3+2] cycloaddition of azomethine ylide proceeded smoothly in the presence of 0.5–1.0 mol% (CyJohnPhos)AuCl/AgOTf at 65 or 80 °C. This strategy with (–)-phenylmenthol-derived iminoester enables a generation of chiral azomethine ylide in situ to construct an optically active pyrroloisoquinoline in a highly diastereoselective manner. An alkyne and alkenes with electron-withdrawing group could be utilized as dipolarophiles. Iminoesters having terminal and internal alkynes were applied as reaction substrates to afford the corresponding pyrroloisoquinolines.

Supporting Information