10.1021/om010672d.s001
Victorio Cadierno
Victorio
Cadierno
Salvador Conejero
Salvador
Conejero
M. Pilar Gamasa
M. Pilar
Gamasa
José Gimeno
José
Gimeno
Miguel A. Rodríguez
Miguel A.
Rodríguez
Activation of Propargylic Alcohols Derived from
Hormonal Steroids by the Indenyl−Ruthenium(II)
Complex [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>]: Experimental and
Theoretical Evidence of an
Allenylidene−Vinylvinylidene Equilibrium
American Chemical Society
2001
Ru
Theoretical Evidence
nucleophilic addition
PMe 2 Ph
electrophilic C γ atom
RuCl
allenylidene 3
Hormonal Steroids
vinylvinylidene tautomer
disubstituted vinylvinylidene complexes 6
PH
vinylvinylidenes 4
vinylvinylidene 4
NaPF 6
kcal
reaction mixtures
equilibrium mixtures
Propargylic Alcohols Derived
PPh
allenylidenes 3
Ab initio
MeOSO 2 CF 3
tautomerization process
K 2 CO 3
activation energy
2001-12-11 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Activation_of_Propargylic_Alcohols_Derived_from_Hormonal_Steroids_by_the_Indenyl_Ruthenium_II_Complex_RuCl_sup_5_sup_-C_sub_9_sub_H_sub_7_sub_PPh_sub_3_sub_sub_2_sub_Experimental_and_Theoretical_Evidence_of_an_Allenylidene_Vinylvinylidene_Equilibrium/3767157
The indenyl−ruthenium(II) complex [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>] (<b>1</b>) reacts with ethisterone
(<b>2a</b>), 17α-ethynylestradiol (<b>2b</b>), and mestranol (<b>2c</b>), in methanol and in the presence of NaPF<sub>6</sub>,
to afford equilibrium mixtures containing the corresponding allenylidene <b>3a</b>−<b>c</b> and
vinylvinylidene <b>4a</b>−<b>c</b> tautomers. Deprotonation of these mixtures with K<sub>2</sub>CO<sub>3</sub> allows the
preparation of σ-enynyl derivatives <b>5a</b>−<b>c</b>, which can be selectively alkylated with MeOSO<sub>2</sub>CF<sub>3</sub> to yield disubstituted vinylvinylidene complexes <b>6a</b>−<b>c</b>. Displacement of these equilibriums can also be accomplished by treatment of the reaction mixtures with acetonitrile or
PMe<sub>2</sub>Ph. Thus, while in the first case terminal 1,3-enynes <b>7a</b>−<b>c</b> are selectively obtained by
demetalation of vinylvinylidenes <b>4a</b>−<b>c</b>, phosphonio-alkynyl complexes <b>9a</b>−<b>c</b> are exclusively
formed in the second case as the result of the nucleophilic addition of PMe<sub>2</sub>Ph on the
electrophilic C<sub>γ</sub> atom of allenylidenes <b>3a</b>−<b>c</b>. Ab initio molecular orbital calculations on the
models [Ru{CCC(H)CH<sub>3</sub>}(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(PH<sub>3</sub>)<sub>2</sub>]<sup>+</sup> and [Ru{CC(H)CHCH<sub>2</sub>}(η<sup>5</sup>-C<sub>5</sub>H<sub>5</sub>)(PH<sub>3</sub>)<sub>2</sub>]<sup>+</sup> show that the vinylvinylidene tautomer is only 2.1 kcal/mol more stable than the
allenylidene. The spontaneous tautomerization process between both complexes, which
involves a [1,3]-hydrogen sigmatropic rearrangement, requires an activation energy of 66.5
kcal/mol.