T1 - Metathesis reactions in total synthesis

(Chemical Equation Presented) A tandem reaction sequence involving relay metathesis-induced enyne RCM and metallotropic [1,3]-shift is an effective tool to construct cyclic alkenes with embedded 1,5-dien-3-yne moieties from acyclic precursors containing a 1,3-diyne. Total syntheses of (+)-asperpentyn, (-)-harveynone, and (-)-tricholomenyn A have been accomplished by implementing this metathesis-based tandem reaction sequence as the key step.

Application of tandem ring-closing enyne metathesis: Formal total synthesis of (-)-cochleamycin A
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(Chemical Equation Presented) With the exception of palladium-catalyzed cross-couplings, no other group of reactions has had such a profound impact on the formation of carbon-carbon bonds and the art of total synthesis in the last quarter of a century than the metathesis reactions of olefins, enynes, and alkynes. Herein, we highlight a number of selected examples of total syntheses in which such processes played a crucial role and which imparted to these endeavors certain elements of novelty, elegance, and efficiency. Judging from their short but impressive history, the influence of these reactions in chemical synthesis is destined to increase.


Synthesis of (+)anatoxin a using enyne metathesis

KW - Alkene metathesis
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Relay the catalyst! A concise synthesis of the naturally occurring inhibitor of ubiquitin-activating enzyme (+)-pane- pophenanthrin has been achieved. The synthesis features a relay metathesis-induced enyne-ring-closing metathesis followed by cross-metathesis to form a pivotal intermediate. Several step manipulations of this intermediate afforded a putative biomimetic Diels-Alder reaction substrate that induced a spontaneous dimerization, thereby providing (+)-panepophenanthrin.


The Chemical Record 2016 , 16 , 124

A tandem reaction sequence involving relay metathesis-induced enyne RCM and metallotropic [1,3]-shift is an effective tool to construct cyclic alkenes with embedded 1,5-dien-3-yne moieties from acyclic precursors containing a 1,3-diyne. Total syntheses of (+)-asperpentyn, (-)-harveynone and (-)-tricholomenyn A have been accomplished by implementing this metathesis-based tandem reaction sequence as the key step.

Substituted arene synthesis by olefination, arylation or …

Epoxyquinoids, a subclass of naturally occurring cyclohexane epoxides, display a broad range of structural variation and impressive biological activities, and thus have elicited significant synthetic and biological studies. Among many naturally occurring epoxyquinoids, (+)-asperpentyn, (-)-harveynone and its prenylated homolog (-)-tricholomenyn A have an embedded 1,5-dien-3-yne moiety (). Due to this structural characteristic, Ogasawara, Johnson, Taylor, Maycock, Negishi, and Kitahara utilized Pd-catalyzed Sonagashira or Stille coupling between the preformed 2-bromo- or iodocyclo-hexenone derivatives (bromoxone or its iodo analogue) and appropriate 1,3-enyne counterparts for their total syntheses.

Cross Metathesis - Organic Chemistry Portal

AB - (Chemical Equation Presented) A tandem reaction sequence involving relay metathesis-induced enyne RCM and metallotropic [1,3]-shift is an effective tool to construct cyclic alkenes with embedded 1,5-dien-3-yne moieties from acyclic precursors containing a 1,3-diyne. Total syntheses of (+)-asperpentyn, (-)-harveynone, and (-)-tricholomenyn A have been accomplished by implementing this metathesis-based tandem reaction sequence as the key step.