10.1021/jacs.6b07815.s001
David Nieder
David
Nieder
Volker Huch
Volker
Huch
Cem B. Yildiz
Cem B.
Yildiz
David Scheschkewitz
David
Scheschkewitz
Regiodiscriminating
Reactivity of Isolable NHC-Coordinated
Disilenyl Germylene and Its Cyclic Isomer
American Chemical Society
2016
NHC-coordinated cyclic germylenes
6 b display
cyclic 6 b
DFT
low-valent germanium center
Si
5 b
cyclopropylidene analogue 6 b
NHC i Pr 2
disilenyl germylene 5 b isomerizes
Isolable NHC-Coordinated Disilenyl Germylene
vinylidene analogue R 2
α- chloro silyl functionalized
2016-09-26 00:00:00
Dataset
https://acs.figshare.com/articles/dataset/Regiodiscriminating_Reactivity_of_Isolable_NHC-Coordinated_Disilenyl_Germylene_and_Its_Cyclic_Isomer/4029321
An isolable NHC-coordinated
disilenyl germylene R<sub>2</sub>SiSiR-GePh·NHC<sup><i>i</i>Pr<sub>2</sub></sup><sup>Me<sub>2</sub></sup> (<b>5b</b>: R = 2,4,6-triisopropylphenyl, NHC<sup><i>i</i>Pr<sub>2</sub></sup><sup>Me<sub>2</sub></sup> = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene)
is obtained from the reaction of the α-chloro silyl functionalized
heavier vinylidene analogue R<sub>2</sub>(Cl)Si-RSiGe·NHC<sup><i>i</i>Pr<sub>2</sub></sup><sup>Me<sub>2</sub></sup> with
phenyllithium. The disilenyl germylene <b>5b</b> isomerizes
at 40 °C to the NHC-adduct of the corresponding heavier cyclopropylidene
analogue <b>6b</b>. Both <b>5b</b> and <b>6b</b> display near perfect regiodiscrimination in their reactions with
phenylacetylene and xylyl isocyanide, affording in the case of each
reagent two different regioisomers of NHC-coordinated cyclic germylenes.
DFT calculations reveal that the SiSi bond accounts for the
high reactivity of <b>5b</b> even at low temperature while in
the case of cyclic <b>6b</b> the low-valent germanium center
requires a considerable thermal activation.