TY - JOUR
T1 - Isomerization of the diphosphine ligand 3,4-bis(diphenylphosphino)-5- methoxy-2(5H)-furanone (bmf) at a triosmium cluster and P-C bond cleavage in the unsaturated cluster 1,1-Os3(CO)9(bmf)
T2 - Synthesis and X-ray diffraction structures of the isomeric Os3(CO) 10(bmf) clusters and HOs3(CO)8(μ-C 6H4)
AU - Kandala, Srikanth
AU - Yang, Li
AU - Campana, Charles F.
AU - Nesterov, Vladimir
AU - Wang, Xiaoping
AU - Richmond, Michael G.
PY - 2010/9/22
Y1 - 2010/9/22
N2 - The labile cluster 1,2-Os3(CO)10(MeCN)2 (1) reacts with the chiral diphosphine ligand 3,4-bis(diphenylphosphino)-5- methoxy-2(5H)-furanone (bmf) to furnish 1,2-Os3(CO)10(bmf) (2a) in high yield. Heating cluster 2a over the temperature range 358-383 K under CO leads to isomerization of the bmf ligand and formation of the diphosphine-chelated cluster 1,1-Os3(CO)10(bmf) (2b) and an equilibrium mixture consisting of 2a and 2b in a 15:85 ratio. Extended thermolysis of an equilibrium mixture of Os3(CO)10(bmf) is accompanied by CO loss and ortho-metalation of an aryl ring to afford an inseparable mixture of three diastereomeric hydride clusters HOs 3(CO)9(C29H23O3P 2) (3a-c). Thermolysis of HOs3(CO)9(C 29H23O3P2) (3a-c) in refluxing toluene leads to P-C bond cleavage and formation of the benzyne-substituted clusters HOs3(CO)8(μ-C6H4)(μ- C23H19O3P2) (4a,b) as a 4:1 mixture of diastereomers. The unequivocal identity of the major benzyne-substituted cluster has been determined by X-ray diffraction analysis, where the activation of one of the phenyl groups situated α to the furanone carbonyl group in the bmf ligand has been established. The isomerization and activation of the bmf ligand are contrasted with other Os3(CO)10(diphosphine) derivatives prepared by our groups.
AB - The labile cluster 1,2-Os3(CO)10(MeCN)2 (1) reacts with the chiral diphosphine ligand 3,4-bis(diphenylphosphino)-5- methoxy-2(5H)-furanone (bmf) to furnish 1,2-Os3(CO)10(bmf) (2a) in high yield. Heating cluster 2a over the temperature range 358-383 K under CO leads to isomerization of the bmf ligand and formation of the diphosphine-chelated cluster 1,1-Os3(CO)10(bmf) (2b) and an equilibrium mixture consisting of 2a and 2b in a 15:85 ratio. Extended thermolysis of an equilibrium mixture of Os3(CO)10(bmf) is accompanied by CO loss and ortho-metalation of an aryl ring to afford an inseparable mixture of three diastereomeric hydride clusters HOs 3(CO)9(C29H23O3P 2) (3a-c). Thermolysis of HOs3(CO)9(C 29H23O3P2) (3a-c) in refluxing toluene leads to P-C bond cleavage and formation of the benzyne-substituted clusters HOs3(CO)8(μ-C6H4)(μ- C23H19O3P2) (4a,b) as a 4:1 mixture of diastereomers. The unequivocal identity of the major benzyne-substituted cluster has been determined by X-ray diffraction analysis, where the activation of one of the phenyl groups situated α to the furanone carbonyl group in the bmf ligand has been established. The isomerization and activation of the bmf ligand are contrasted with other Os3(CO)10(diphosphine) derivatives prepared by our groups.
KW - Crystallography
KW - Diphosphine ligand
KW - Ligand substitution
KW - Osmium clusters
KW - P-C bond-activation
UR - http://www.scopus.com/inward/record.url?scp=77956266458&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2010.07.003
DO - 10.1016/j.poly.2010.07.003
M3 - Article
AN - SCOPUS:77956266458
SN - 0277-5387
VL - 29
SP - 2814
EP - 2821
JO - Polyhedron
JF - Polyhedron
IS - 14
ER -