Hydrochlorination of Ruthenaphosphaalkenyls: Unexpectedly Facile Access to Alkylchlorohydrophosphane
Complexes
Victoria
K. Greenacre
Iain J. Day
Ian R. Crossley
10.1021/acs.organomet.6b00829.s001
https://acs.figshare.com/articles/journal_contribution/Hydrochlorination_of_Ruthenaphosphaalkenyls_Unexpectedly_Facile_Access_to_Alkylchlorohydrophosphane_Complexes/4540921
The novel ruthenaphosphaalkenyls
[Ru{PC(H)SiMe<sub>2</sub>R}Cl(CO)(PPh<sub>3</sub>)<sub>2</sub>] (R = <i>p</i>-C<sub>6</sub>H<sub>4</sub>CF<sub>3</sub>, <i><sup>n</sup></i>Bu) have been prepared for the first
time, and studied alongside
precedent analogues (R = Me, Ph, <i>p</i>-tol) for their
reactions with HCl. In contrast to chemistry defined
for the <i>tert</i>-butyl congener [Ru{PC(H)<sup><i>t</i></sup>Bu}Cl(CO)(PPh<sub>3</sub>)<sub>2</sub>], which initially adds a single equivalent of HCl across
the Ru–P linkage, all five silyl derivatives undergo spontaneous
addition of a second equivalent to afford [Ru{η<sup>1</sup>-PHCl–CH<sub>2</sub>SiMe<sub>2</sub>R}Cl(CO)(PPh<sub>3</sub>)<sub>2</sub>], extremely rare examples of coordinated “PHXR”
type ligands. Where R = SiMe<sub>3</sub>, a distorted octahedral geometry
with a conformationally restricted “PHXR” ligand is
observed crystallographically; this structure is appreciably retained
in solution, as determined from multinuclear NMR spectroscopic features,
which include a Karplus-like P<sub>PPh3</sub>–Ru–P–H
spin–spin coupling dependence. Computational data suggest a
silyl-induced increase in negative charge density at the phosphaalkenic
carbon, rather than an intrinsic thermodynamic driver, as the likely
origin of the disparate reactivity.
2017-01-11 14:21:12
Ru
n Bu
precedent analogues
PHXR
novel ruthenaphosphaalkenyls
silyl-induced increase
multinuclear NMR spectroscopic features
equivalent
Alkylchlorohydrophosphane Complexes
Computational data
ligand
silyl derivatives
HCl
butyl congener
charge density
Unexpectedly Facile Access
C 6 H 4 CF 3
SiMe 3
octahedral geometry