J. Kowalczyk, S. Agbossou, J. Gladysz
Nov 13, 1990
Citations
0
Influential Citations
19
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract Reaction of (η 5 -C 5 H 5 )Re(NO)(PPh 3 )(CH 3 ) ( 1 ) and HBF 4 · OEt 2 in C 6 H 5 Cl at −45°C gives the chlorobenzene complex [(η 5 -C 5 H 5 )Re(NO)(PPh 3 )(ClC 6 H 5 )] + BF − 4 ( 5 ). The rhenium is bound chiefly to chlorine in 5 , but other species, possibly η 2 -arene isomers, are apparent by 31 P NMR. The relative amounts change upon warming, and new species appear. Complex 5 reacts with neutral donor ligands L (CH 3 CN, C 6 H 5 CH 2 CH=CH 2 , THF) to give the corresponding adducts [(η 5 -C 5 H 5 )Re(NO)(PPh 3 )(L)] + BF − 4 , halide ions X − to give halide complexes (η 5 -C 5 H 5 )Re(NO)(PPh 3 )(X), and HSi(OEt) 3 to give hydride complex (η 5 -C 5 H 5 )Re(NO)(PPh 3 )(H) (74–91%). When 5 is generated from optically active 1 , analogous reactions with L ((−)-( S )-2-phenylbutyronitrile, benzaldehyde) give adducts in high optical yields and with overall retention of configuration at rhenium. For example, carboxylate complex (+)-( RR )-(η 5 -C 5 H 5 )Re(NO)(PPh 3 )(O(C=O)-CH(OAc)C 6 H 5 ) forms in > 99% d.e. upon treatment of 5 derived from (+)-( S )- 1 with (−)-( R )-C 6 H 5 CH(OAc)COOH and then base. Thus, 5 serves as a functional equivalent of the chiral Lewis acid [(η 5 -C 5 H 5 )Re(NO)(PPh 3 )] + —superior in many aspects to the analogous dichloromethane complex reported earlier.