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Total Synthesis of Quebrachamine through Macrolactamization
Author(s) -
Hsu ShihWen,
Cheng HsiuYi,
Huang AnChi,
Ho TseLok,
Hou DuenRen
Publication year - 2014
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201400064
Subject(s) - sonogashira coupling , chemistry , alkyne , iodide , indole test , lithium iodide , total synthesis , lithium (medication) , combinatorial chemistry , copper , stoichiometry , chemical synthesis , organic chemistry , medicinal chemistry , catalysis , palladium , medicine , biochemistry , electrode , electrolyte , in vitro , endocrinology
The total synthesis of quebrachamine was achieved through the macrolactamization of cis ‐2‐alkenylated indole 17 , which was prepared by a Sonogashira reaction between indole 5b and piperidine 11 followed by cis ‐hydrogenation. We found that stoichiometric copper(I) iodide limited the undesired Glaser‐type homocoupling of alkyne 11 that would otherwise take place during the Sonogashira coupling. This direct approach allowed the total synthesis in ten linear steps starting from commercially available chemicals. Conditions for the reduction of lactam 19 by lithium aluminiumhydride were adjustable, so that either (±)‐quebrachamine or the analogue (±)‐kopsiyunnanine D was prepared.