Portal de Periódicos da CAPES

(η5-Pentamethylcyclopentadienyl)rhodium(III) complexes bearing η1-P and η2-phosphino-phenoxide coordinations derived from (2,6-dimethoxyphenyl)diphenylphosphine: their preparation and reactions with Lewis bases

1998; Elsevier BV; Volume: 561; Issue: 1-2 Linguagem: Inglês

10.1016/s0022-328x(98)00523-3

1872-8561

Xiao-Hong Han, Yasuhiro Yamamoto,

Synthetic Organic Chemistry Methods

Abstract Reaction of [Cp*RhCl2]2 with (2,6-dimethoxyphenyl)diphenylphosphine (MDMPP) gave Cp*RhCl2(MDMPP-P) 2 and Cp*RhCl(MDMPP-P,O) 5, depending on the reaction conditions. Treatment of 2 with NaPF6 formed the O-coordination complex, [Cp*RhCl(MDMPP-P,OMe)](PF6) 3. Complex 3 was reconverted to 2 by treatment with [N(CH2Ph)Et3]Cl. Reactions of 3 with isocyanide, carbon monoxide or P(OCH2)3CMe eliminated the O-coordination to give the corresponding complexes [Cp*RhCl(MDMPP-P)(L)](PF6) 4 (L=CO (a), 2,6-Me2C6H3NC (b), p-TosCH2NC (c), and P(OCH2)3CMe) (d). Complex 5 reacted with Lewis bases (L) in the presence of NaPF6 to produce [Cp*Rh(MDMPP-P,O)(L)](PF6) 6 and could be also obtained from 3 and MDMPP. The CO ligand of 4a or 6a was labile and was replaced with isocyanide or phosphine to produce the corresponding complexes, whereas its reverse reaction did not occur. Conversion of 4d to 6d was also observed, but conversion from 4 to 6 did not occur in other complexes. X-ray analyses of 2, 4a, 5 and 6a·C6H6 were performed and showed that the complexes have the piano-stool structure; 2: triclinic, P1 (no. 2), a=10.639(3), b=15.965(3), c=8.800(3) A, α=94.43(2), β=103.75(3), γ=88.62(2)°, V=1447.4(7) A3, Z=2, R=0.039, Rw=0.042; 4c (L=p-TosCH2NC): orthorhombic, Pna21 (no. 33), a=26.817(4), b=17.662(5), c=8.673(4) A, V=4108(1) A3, Z=4, R=0.040, Rw=0.042; 5: orthorhombic, Pbca (no. 61), a=8.212(8), b=17.808(10), c=35.96(1) A, V=5259(4) A3, Z=8, R=0.040, Rw=0.042; 6a·C6H6 (L=CO): monoclinic, C2/c (no. 15), a=33.29(2), b=8.567(5), c=29.26(3) A, β=124.51(3)°, V=6877(7) A3, Z=8, R=0.040, Rw=0.042.