Premium
The Nicholas Approach to Natural Product Hybrids
Author(s) -
Álvaro Elsa,
de la Torre María C.,
Sierra Miguel A.
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200600136
Subject(s) - enyne , chemistry , intramolecular force , stereoselectivity , terpene , natural product , intermolecular force , indole test , stereochemistry , conjugated system , allyl alcohol , selectivity , alcohol , organic chemistry , combinatorial chemistry , molecule , catalysis , polymer
Abstract The intermolecular Nicholas reaction of terpene‐based scaffolds is an excellent access to natural product hybrid compounds. These intermolecular reactions have a low selectivity and are scarcely efficient for non‐conjugated cations, but they are highly efficient to produce new terpene structures through an intramolecular reaction pathway. The use of cations derived from natural product derived [Co 2 (CO) 6 ]–enyne complexes is, in contrast, a highly efficient regio‐ and stereoselective procedure to prepare very complex structures, incorporating diverse densely functionalized or labile moieties. Thus, β‐pinene–diterpene–alkaloid or homohybrids can be accessed in totally stereo‐, regio‐ and siteselective fashion. This approach efficiently discriminates between different propargylic positions by selecting the nature of the alcohol, being the enyne‐derived cations the most reactive. The chimera 38 with a steroid–terpene–indole skeleton was prepared in this way.