Catalytic Transformations of Alkynes via Ruthenium Vinylidene and Allenylidene Intermediates

endo-Selective Iron Catalysts for Intramolecular Alkyne Hydrofunctionalization

“…Metal vinylidenes, MCCRR′, are key intermediates in many C–E bond-forming reactions, including hydration, hydroalkoxylation, hydroamination, and hydrophosphination. − A highly electrophilic α carbon is characteristic of a metal vinylidene, which directs nucleophilic attack to this site and selectively affords new C–E bonds (E = O, N, P, S) in the resulting metal alkylidene or vinyl complexes. This reactivity has been exploited in catalysis with a selection of metals (Ru, Rh, Os, W) for the catalytic intermolecular hydrofunctionalization of alkynes with water, alcohols, amides, carbamates, etc.…”

Facile synthesis of polycyclic metallaarynes

“…The strategy was devised on the basis of the retrosynthetic analysis shown in Scheme 2 . It is known that phosphorus ylides can act as genuine carbene transfer agents 9 and that alkyne complexes L n M(R′C CR) (R = H, 10 SiMe 3 ( ref. 11 )) can rearrange to give vinylidene complexes L n M{ C C(R′)(R)} via a 1,2-R shift.…”

Ruthenium‐Catalyzed Cycloisomerization of 2,2′‐Diethynyl‐ biphenyls Involving Cleavage of a Carbon–Carbon Triple Bond

“…In most of the catalytic processes, reactions of the intermediate metal–vinylidene complexes are associated with their metal–carbon double bond. On the other hand, the carbon–carbon double bonds of the metal–vinylidene complexes are also reactive to participate in various pericyclic reactions ,,. However, there have been no examples of catalytic reactions in which the carbon–carbon double bond of the metal vinylidenes undergoes a [2+2] cycloaddition with a carbon–carbon unsaturated bond .…”