BASE-PROMOTED HYDROALKYLATION REACTIONS OF THE ETA(5)-C(5)ME(5) LIGAND COORDINATED TO RHODIUM - PROBING A MECHANISM - NEW COMPOUNDS WITH THE ETA(5)-C(5)ME(4)CF(3) LIGAND
Lp. Barthelrosa et al., BASE-PROMOTED HYDROALKYLATION REACTIONS OF THE ETA(5)-C(5)ME(5) LIGAND COORDINATED TO RHODIUM - PROBING A MECHANISM - NEW COMPOUNDS WITH THE ETA(5)-C(5)ME(4)CF(3) LIGAND, Organometallics, 15(19), 1996, pp. 3924-3934
Dichloro(pentamethylcyclopentadienyl)rhodium(III) dimer, [{(eta(5)-C(5
)Me(5))RhCl2}(2)] (1), reacts with diphenylvinylphosphine to produce [
(eta(5)-C(5)Me(5))Rh{CH2CHP(C6H5)(2)}Cl-2] (2) and [(eta(5)-C(5)Me(5))
Rh{CH2CHP(C6H5)(2)}Cl-2]X (3, X = Cl- (a), PF6- (b)). In acetonitrile,
compound 1 undergoes a base-promoted hydroalkylation reaction with po
tassium tert-butoxide and diphenylvinylphosphine to produce a(5)-C(5)M
e(3)-1,3-[CH2CH2CH2P(C6H5)(2)](2)}RhCl]X (4, X = Cl- (a), PF6- (b), BP
h(4)(-) (c)) and a(5)-C(5)Me(3)-1,2-[CH2CH2CH2P(C6H5)(2)](2)}RhCl]X (5
, X = Cl- (a), PF6- (b), BPh(4)(-) (c)). Compounds 4a-c and 5a-c conta
in chelating 1,3- and 1,2- iphenylphosphino)propyl)trimethylcyclopenta
dienide ligands. Compounds 2 and 3 are precursors on the pathway towar
d formation of 4a and 5a. Compound 1 reacts with allyldiphenylphosphin
e to produce [(eta(5)-C(5)Me(5))Rh{CH2CHCH2P(C6H5)(2)}Cl-2] (6) and [(
eta(5)-C(5)Me(5))Rh{CH2CHCH2P(C6H5)(2)}Cl-2]X (7, X = Cl- (a), PF6- (b
)). In acetonitrile, compound 1 reacts with allyldiphenylphosphine in
the presence of potassium tert-butoxide to produce a complex mixture o
f products that may contain hydroalkylation adducts. rifluoromethyl)te
tramethylcyclopentadienyl}rhodium (III) dimer, [{(eta(5)-C(6)Me(4)CF(3
))RhCl2}(2)] (8), reacts with diphenylvinylphosphine to produce [(eta(
5)-C(6)Me(4)CF(3))Rh{CH2CHP(C6H5)(2)}Cl-2] (9), however the bis(phosph
ine) analog cannot be isolated or characterized. In refluxing ethanol,
compound 8 reacts with diphenylvinylphosphine in the absence of potas
sium tert-butoxide to undergo hydroalkylation accompanied by conversio
n of the CF3 group into a carboethoxy functionality producing )-C-5(CO
(2)Et)Me(3)-2-[CH2CH2CH2P(C6H5)(2)]}RhCl2] (10). Complexes 3b, 7b, and
10 were characterized by single-crystal X-ray crystallography.