Photochemical Intermolecular Oxidative Addition of the C−Cl Bond of Chlorobenzene to Rhenium

Abstract

The phenyl chloride complexes Cp*Re(CO)(L)(Ph)Cl (L ) P(OEt) 3 (6), Pc (7), P(OMe) 3 (8), and PMe 2 Ph (9)) have been prepared by irradiation of the corresponding rhenium dinitrogen complex Cp*Re(CO)(L)(N 2 ) in chlorobenzene. In the case of L ) P(OPh) 3 the result was instead the formation of the cyclometalated complex Cp*Re(CO){η 2 -P(OC 6 H 4 )(OPh) 2 }H (10), arising from intramolecular C-H oxidative addition of a phenyl group of the phosphine oxide ligand.

Anionic phosph(in)ito (“phosphoryl”) ligands: Non-classical “actor” phosphane-type ligands in coordination chemistry

“…The tentatively proposed structure for the binuclear complex with the formal Re=Re double bond to fulfill an 18-electron count for each Re is in accord with the spectroscopic data. Unfortunately, all attempts to obtain an X-ray structure of 13 have failed [61]. As mentioned earlier, most Arbuzov-like rearrangements involving phosphite transition metal complexes are brought by nucleophiles, and A c c e p t e d M a n u s c r i p t [62].…”

“…Scheme 7. Arbuzov rearrangements in the coordination sphere of rhenium 12 [61] and rhodium 14 [63] metal precursors to form the corresponding  1 -P−phosphonate complexes 13 and 15. [70].…”

Agostic bonds in cyclometalation

“…On the other hand, the irradiation of Cp * Re(CO)(P (OPh) 3 )N 2 afforded a cis isomer, agostic product 44 which slowly decayed away in favor of cis(P,H) 44 as shown in Eq. (41) [83].…”

“…Other g-CeH agostic compounds were reported on phenylphosphines [80a,80b], cyclohexyphosphines [113,114], tert-butylphosphines [115e117], iso-propylphosphines [118e120], and phosphites [83].…”

η²-COORDINATION OF CHLOROBENZENES TO RHENIUM FRAGMENT Cp*Re(CO)2: CHEMICAL AND PHOTOCHEMICAL SYNTHESES OF Cp*Re(CO)2(η²-C6H6-nCl n)

“…[3][4][5] Similar result have been found by Leiva and Sutton in the reaction of several dinitrogen complexes Cp*Re(CO)(L)N 2 (L = phosphine and phosphite) with chlorobenzene. 6 As far as we are aware the h 2 -coordination of chloroarenes to rhenium remains elusive. On this regard, Gladysz has documented the ligation of chlorobenzene at low temperature in the cationic complex [Cp*Re(NO)(PPh 3 )(C 6 H 5 Cl)] + .…”