Synthesis and Reactivity of Labile MeCN Adducts of Diruthenium Bis(μ-methylene) Species, Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)<sub>2</sub>(CO)<i><sub>n</sub></i>(MeCN)<sub>2-<i>n</i></sub> (<i>n</i> = 1, 2): Reaction with H Sources, H−X (X = SiR<sub>3</sub>, SnR<sub>3</sub>, H), and C−C Coupling with Alkynes and Diazoalkanes
journal contribution
posted on 1997-12-09, 00:00 authored by Munetaka Akita, Ruimao Hua, Sadahiro Nakanishi, Masako Tanaka, Yoshihiko Moro-okaIrradiation of the diruthenium bis(μ-methylene) complex
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)<sub>2</sub>(CO)<sub>2</sub>
(<b>1</b>), in
acetonitrile gives the mono- and bis(acetonitrile) species
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)<sub>2</sub>(CO)(MeCN)
(<b>2</b>) and
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)<sub>2</sub>(MeCN)<sub>2</sub>
(<b>3</b>) in a successive manner. The mono-MeCN species<b>
2</b> has been
characterized spectroscopically and crystallographically, but the
bis-MeCN species <b>3</b> is too
unstable to be fully characterized. Reaction of <b>2</b> with
hydrosilanes and hydrostannanes
results in oxidative addition of the H−Si and H−Sn bond to give
hydrido−μ-methylene
complexes,
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)<sub>2</sub>(H)(mR<sub>3</sub>)(CO)
(m = Si (<b>7</b>), Sn (<b>9</b>)). In the case of the
reactions
with dihydrosilane, phenylsilane, and triphenylstannane, one of the two
methylene bridges
is eliminated as methane (and benzene from phenylsilane) to give
μ-methylene−μ-silylene
complexes,
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)(μ-SiR<sub>2</sub>)(H)(SiR<sub>3</sub>)(CO)
(<b>8</b>), and a tristannyl−μ-methylene complex,
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CH<sub>2</sub>)(μ-H)(SnPh<sub>3</sub>)<sub>3</sub>(CO)
(<b>10</b>). Treatment of <b>2</b> with alkynes
(R<sup>1</sup>C⋮CR<sup>2</sup>) and diphenyldiazomethane produces the metallacyclic products
Cp<sub>2</sub>Ru<sub>2</sub>[μ-η<sup>3</sup>-C(R<sup>1</sup>)C(R<sup>2</sup>)CH<sub>2</sub>](μ-CH<sub>2</sub>)(CO) (<b>12</b>), and the vinylidene complex
Cp<sub>2</sub>Ru<sub>2</sub>(μ-CCPh<sub>2</sub>)(μ-η<sup>3</sup>-CPh<sub>2</sub>)
(<b>14</b>), respectively,
via C−C coupling. In contrast to <b>2</b>, corresponding
reactions of the bis-MeCN species <b>3</b> are
sluggish and only the simple MeCN replacement reaction proceeds in a
selective manner.
