New Chiral Cyclopentadienylrhenium Lewis Acids Featuring Fluorinated Triarylphosphanes and Enhanced Acceptor Abilities − An Unusual Carbon−Fluorine Bond Activation in a Metal Coordination Sphere
✍ Scribed by Wolfgang Mohr; Gene A. Stark; Haijun Jiao; J. A. Gladysz
- Publisher
- John Wiley and Sons
- Year
- 2001
- Tongue
- English
- Weight
- 421 KB
- Volume
- 2001
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
The acetonitrile complex [(η 5 -C 5 H 5 )Re(NO)(NCCH 3 )(CO)] + BF 4
-(1) and P(4-C 6 H 4 CF 3 ) 3 slowly react (2 d, room temperature) to give the substitution product [(η 5 -C 5 H 5 )Re(NO){P(4-C 6 H 4 CF 3 ) 3 }(CO)] + BF 4 -(3, 85%). The reaction of 1 and less nucleophilic P(C 6 F 5 ) 3 must be conducted in a melt at 140 °C, but [(η 5 -C 5 H 5 )Re(NO){P(C 6 F 5 ) 3 }(CO)] + BF 4 -(11) is isolated in 90% yield. Reduction of 3 by NaBH 4 gives the methyl complex (η 5 -C 5 H 5 )Re(NO){P(4-C 6 H 4 CF 3 ) 3 }(CH 3 ), which is treated with TfOH and H 3 CN=C(H)C 6 H 5 to give the imine complex [(η 5 -C 5 H 5 )Re(NO)(PPh 3 ){N(CH 3 )=C(H)C 6 H 5 }] + TfO -(9). Complex 9 was, like the non-fluorinated analog, unreactive towards allyltin nucleophiles. Complex 11 should lead to a [a] Institut für Organische Chemie,