Synthesis of chiral oxacyclic dienes via ruthenium-catalyzed enyne metathesis: useful building blocks for chiral tricyclic oxygen derivatives

Rate Enhancement by Ethylene in the Ru‐Catalyzed Ring‐Closing Metathesis of Enynes: Evidence for an “Ene‐then‐Yne” Pathway that Diverts through a Second Catalytic Cycle

“…The beneficial effect of ethylene on some RCM reactions has led to “Mori's conditions”10 being widely adopted7a, 12 to increase yields and inhibit side reactions such as epimerization,12d and substrate homo‐cross‐metathesis 12c,g. The origin of the ethylene effect has been ascribed to the attenuation of unproductive resting states in equilibrium with the ruthenium methylidene 9 in cycle A 10.…”

Facile, Efficient and Chemoselective Palladium(0)-Catalyzed Isomerization of 2-Vinylidenehydrofurans into Valuable Functionalized 1,3-Dienes

“…Interestingly, furanyl dienes constitute useful building blocks for the selective construction of heterocyclic frameworks via Diels-Alder reaction encountered in many naturally occurring compounds. 13 Although, the enyne metathesis 14 and the tungsten-mediated cycloalkenation 15 have emerged recently as powerful entries to these valuable dienes, the availability of highly functionalized intermediates often requires long procedures and still constitutes a challenging problem which justifies the need for the discovery of new simple approaches. Although the isomerization of allene to 1,3diene is a well-known process.…”

Enyne Metathesis Catalyzed by Ruthenium Carbene Complexes

“…There are a number of examples where enyne metathesis and cycloaddition reactions have been carried out in a step-wise fashion and not as a tandem process. 42,45,[51][52][53][54][55][56] Several of these also deserve to be noted. Mori 42 and Blechert 45 have both prepared fairly complex ring systems by the combination of enyne metathesis and a cycloaddition reaction.…”