The nicholas approach to natural product hybrids.
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, beta-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.
Alvaro
Elsa
E
Instituto de Química Orgánica, Dpto. de Productos Naturales, CSIC, C/Juan de la Cierva 3, 28006 Madrid, Spain.
de la Torre
María C
MC
Sierra
Miguel A
MA
D000480:Alkynes / Q000138:chemical synthesis* / Q000737:chemistry; D000081008:Bicyclic Monoterpenes; D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D004224:Diterpenes / Q000737:chemistry; D020005:Propanols / Q000737:chemistry; D013729:Terpenes / Q000737:chemistry*
D000480:Alkynes; D000081008:Bicyclic Monoterpenes; D001688:Biological Products; D004224:Diterpenes; D020005:Propanols; D013729:Terpenes; C109395:sclareolide; D003035:Cobalt; C061545:myrtenal; C028255:propargyl alcohol