TY - JOUR
T1 - Convenient syntheses of novel ruthenium catalysts bearing N-heterocyclic carbenes
AU - Baratta, Walter
AU - Herrmann, Wolfgang A.
AU - Rigo, Pierluigi
AU - Schwarz, J. ürgen
PY - 2000/1/15
Y1 - 2000/1/15
N2 - The 16-electron ruthenium(II) complexes Cp*Ru[C(R)N(H)C=C(H)N(R)]Cl (Cp*=η5-C5Me5; R=Cy (ICy), 1a; Mes (IMes), 1b) containing N-heterocyclic carbenes are easily accessible in quantitative yields from [Cp*Ru(OMe)]2 (Me=CH3) and the corresponding 1,3-diorganylimidazolium chloride by methanol elimination. Compounds 1a-b can also be prepared in 75-80% yield by treating the commercially available polymeric ruthenium(III) compound [Cp*RuCl2]n with the free 1,3-diorganylimidazolin-2-ylidenes in 1 to 1.5 molar amounts. 1a reacts with CO, PPh3, pyridine and ethyl diazoacetate (EDA) affording the 18-electron derivatives Cp*Ru(ICy)(L)Cl (L=CO, 2; PPh3, 3; py, 4; CHCO2Et, 5). The mixed dicarbene complex 5 is the first isolable ruthenium cyclopentadienyl species bearing a CHCO2Et moiety. Compounds 1a-b catalyze the carbon-carbon coupling of terminal alkynes HC≢CR (R=Ph, SiMe3, tBu, p-Tol) under mild conditions, with the selectivity strongly depending on the substituent R.
AB - The 16-electron ruthenium(II) complexes Cp*Ru[C(R)N(H)C=C(H)N(R)]Cl (Cp*=η5-C5Me5; R=Cy (ICy), 1a; Mes (IMes), 1b) containing N-heterocyclic carbenes are easily accessible in quantitative yields from [Cp*Ru(OMe)]2 (Me=CH3) and the corresponding 1,3-diorganylimidazolium chloride by methanol elimination. Compounds 1a-b can also be prepared in 75-80% yield by treating the commercially available polymeric ruthenium(III) compound [Cp*RuCl2]n with the free 1,3-diorganylimidazolin-2-ylidenes in 1 to 1.5 molar amounts. 1a reacts with CO, PPh3, pyridine and ethyl diazoacetate (EDA) affording the 18-electron derivatives Cp*Ru(ICy)(L)Cl (L=CO, 2; PPh3, 3; py, 4; CHCO2Et, 5). The mixed dicarbene complex 5 is the first isolable ruthenium cyclopentadienyl species bearing a CHCO2Et moiety. Compounds 1a-b catalyze the carbon-carbon coupling of terminal alkynes HC≢CR (R=Ph, SiMe3, tBu, p-Tol) under mild conditions, with the selectivity strongly depending on the substituent R.
KW - Alkyne coupling
KW - Carbenes
KW - Homogeneous catalysis
KW - Ruthenium
UR - http://www.scopus.com/inward/record.url?scp=0034649983&partnerID=8YFLogxK
U2 - 10.1016/S0022-328X(99)00435-0
DO - 10.1016/S0022-328X(99)00435-0
M3 - Review article
AN - SCOPUS:0034649983
SN - 0022-328X
VL - 593-594
SP - 489
EP - 493
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
ER -