Ruthenium cyclopropenyl complex

Ruthenium vinylidene species can be transformed into small carbocyclic rings via carbocyclization reactions. Ruthenium vinylidene complex 2, generated from the electrophilic reaction of alkyne complex 1 with haloalkanes, was deprotonated with "BU4NOH to give the unprecedented neutral cyclopropenyl complex 3 (Scheme 6.2) [5]. Gimeno and Bassetti prepared ruthenium vinylidene species 4a and 4b bearing a pendent vinyl group when these complexes were heated in chloroform for a brief period, cyclobutylidene products 5a and Sb formed via a [2 + 2] cycloaddition between the vinylidene Ca=Cp bond and olefin (Scheme 6.3) [6]. 

Synthetic and dynamic NMR studies of the ri3-triphenyl and Ti3-trimethylcyclopropenyl complexes [(ti -C5R5)Ru(ti3-C3R 3)X2] (R = H, Me R = Me, Ph X = Cl, Br, I) have been reported and the barrier to rotation of the ri3-cyclopropenyl ligands in isoelectronic molydenum and ruthenium complexes has been investigated using Extended Huckel molecular orbital calculations. 

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