Synthesis, reactivity and molecular structure of phosphino tetramethyl cyclopentadienyl complex (η5: η1-C5Me4CH2PPh2)Re(CO)2

Abstract

The fulvene complex (eta(6)-C(5)Me(4)CH(2))Re(C(6)F(5))(CO)(2) reacts at the exocyclic methylene carbon with potassium diphenylphosphide to yield the anionic species [(eta(5)-C(5)Me(4)CH(2)PPh(2))Re(C(6)F(5))(CO)(2)](-) (). Protonation of with HCl at 0 degrees C produces the hydride complex trans-(eta(5)-C(5)Me(4)CH(2)PPh(2))Re(C(6)F(5))(H)(CO)(2) (). Thermolysis of a hexanes solution of , under nitrogen atmosphere, produces the chelated complex (eta(5):eta(1)-C(5)Me(4)CH(2)PPh(2))Re(CO)(2) () in good yield. The thermolysis under a CO atmosphere affords a mixture of the complexes (eta(5):eta(1)-C(5)Me(4)CH(2)PPh(2))Re(CO)(2) () and (eta(5)-C(5)Me(4)CH(2)PPh(2))Re(CO)(3) (). The reaction of with two electron donor ligands yields (eta(5)-C(5)Me(4)CH(2)PPh(2))Re(CO)(2)(L) (, L = CO; , L = PMe(3); , L = (t)BuNC). Complex also reacts with I(2), HBF(4) and MeOTf to yield the cationic compounds trans-[(eta(5):eta(1)-C(5)Me(4)CH(2)PPh(2))Re(R)(CO)(2)](+) (, R = I; , R = H; , R = Me). Upon treatment with chloroform, the hydride complex converts to the corresponding chloro derivative . The trans stereochemistry for complexes have been assigned on basis of nu(CO) IR intensities and (13)C-NMR chemical shifts. The reaction of the cationic complexes (, ) with KI and Me(3)NO.2H(2)O yields the neutral species cis-(eta(5):eta(1)-C(5)Me(4)CH(2)PPh(2))Re(I)(R)(CO) (, R = I, , R = Me). The molecular structure of and have been determined by X-ray crystallography.

Synthesis and reactivity of η5-tetramethylcyclopentadienyl-propenyl rhenium complexes: Molecular structure of [(η5:η2-C5Me4CH2CHCH2)Re(CO)2]

“…Both IR and NMR parameters are similar to those found in the analogous iodo and fluoroaryl rhenium complexes [trans-(g 5 -C 5 Me 4 CH 2 L)Re(CO) 2 (R)(H)] (L@CH 2 CH@CH 2 , PPh 2 ; R@I, C 6 F 5 ) [11,12].…”

“…The 1 H NMR spectrum of 2a-b in benzene-d 6 showed at low frequency one singlet (d: À8.95 and 9.12, respectively) for the hydride proton; this chemical shift is almost identical to those reported for the closely related complexes [trans-(g 5 -C 5 Me 5 )Re(Aryl F )(CO) 2 (H)] (Aryl F = C 6 F 5 , 2,3,5,6-C 6 HF 4 ) [15] and [trans-(g 5 -C 5 Me 4 CH 2 PPh 2 )Re(C 6 F 5 )(CO) 2 (H)] [12]. The presence of the (propenyl)-tetramethylcyclopentadienyl ligand (C 5 Me 4 CH 2 CH@CH 2 ) in complex 2a-b, were established by 1 H NMR spectroscopy.…”

“…We also have reported that, the fulvene complexes [(g 6 -C 5 Me 4-CH 2 )Re(CO) 2 (R)] (R@I, C 6 F 5 ) react with allylmagnesium chloride, 2-thienyllithium and potassium diphenylphosphide to yield the anionic species [(g 5 -C 5 Me 4 CH 2 L)Re(R)(CO) 2 ] À (L@CH 2 CH@CH 2 ; 2-C 4 H 3 S; PPh 2 ). Protonation with HCl afforded the trans hydride complexes, which under thermolysis conditions (hexane solution under an N 2 atmosphere at 40°C) yielded the compounds [(g 5 :g x -C 5 Me 4 CH 2 L)Re(CO) 2 ] (x = 2 and 1, respectively) [11,12].…”

Recent Advances in the Chemistry of Pentafulvenes

“…Recently, the reaction of complex 441 with KPPh 2 or vinylmagnesium bromide followed by acidic treatment yielded the CpReH complexes 443 and 445 (Scheme ). , …”

“…Recently, the reaction of complex 441 with KPPh 2 or vinylmagnesium bromide followed by acidic treatment yielded the CpReH complexes 443 and 445 (Scheme 125). 369,370 Kreindlin et al obtained various Cp*Ru−fulvene complexes under strongly acidic and oxidizing conditions (Scheme 126). 371 The coordination of β-diketoiminate ligands to [Cp*RuCl 2 ] 2 led in the case of bis-CF 3 -substituted ligand 451 to the Ru(βdiketoiminate)Fv complex 454 (Scheme 127).…”