10.1021/om970703y.s001
Yuan-Te Fu
Yuan-Te
Fu
Pei-Chi Chao
Pei-Chi
Chao
Ling-Kang Liu
Ling-Kang
Liu
Ring Opening of
(Spiro[2.4]hepta-4,6-diene)tricarbonyliron: A Revisit
American Chemical Society
1998
Fe
cation
PPh 3
CO
C 5 H 4
CPh 3
C 5 H 4 CH 2 CH 3
1998-01-19 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Ring_Opening_of_Spiro_2_4_hepta-4_6-diene_tricarbonyliron_A_Revisit/3780852
(Spiro[2.4]hepta-4,6-diene)tricarbonyliron
(<b>2</b>) self-converts to the tethered acyl complex
(CO)<sub>2</sub>FeC(O)CH<sub>2</sub>CH<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)
(<b>3</b>) when refluxed for 1 h in common organic solvents.
The
reaction of <b>2</b> with an external electrophile
(CPh<sub>3</sub><sup>+</sup>, H<sup>+</sup>) opens the
three-membered ring,
resulting in the cation
(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>CH<sub>2</sub>CH<sub>2</sub>R)Fe(CO)<sub>3</sub><sup>+</sup>
whose structure was determined by
spectroscopic methods and confirmed by X-ray analysis of the
PPh<sub>3</sub> derivative
(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>CH<sub>2</sub>CH<sub>3</sub>)Fe(CO)<sub>2</sub>(PPh<sub>3</sub>)<sup>+</sup>.
The reaction of <b>3</b> with a strong electrophile
(CPh<sub>3</sub><sup>+</sup>, Me<sup>+</sup>) affords
the
rotationally restricted Fe−(alkoxy)carbene cation
(CO)<sub>2</sub>FeC(OR)CH<sub>2</sub>CH<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)<sup>+</sup>,
which
can be converted to the Fe−(anilino)carbene cation
(CO)<sub>2</sub>FeC(NHPh)CH<sub>2</sub>CH<sub>2</sub>(η<sup>5</sup>-C<sub>5</sub>H<sub>4</sub>)<sup>+</sup>.