Thomas S. Barnard

Synthesis of 1,3-dioxolanes by the addition of ketones to epoxides by using [Cp*Ir(NCMe)3]2+ as catalyst

Abstract A series of 1,3-dioxolanes have been prepared by the addition of ketones to epoxides in the presence of the catalyst [Cp*Ir(NCMe) 3 ] 2+ , Cp*C 5 Me 5 . The reactions proceed readily at 22°C and the yields are good. The following 1,3-dioxolanes: 2,2,4-trimethyl-1,3-dioxolane, 1 ; 2,2-dimethyl-4-vinyl-1,3-dioxolane, 2 ; 2,2-dimethyl-4-phenyl-1,3-dioxolane, 3 ; 2,2-diethyl-4-methyl-1,3-dioxolane, 4 ; 2,2-diethyl-4-vinyl-1,3-dioxolane, 5 ; 2,2-diethyl-4-phenyl-1,3-dioxolane, 6 were prepared from the appropriate epoxide and carbonyl compounds. An inversion of configuration at the carbon atom at the C–O bond cleavage site of the epoxide was observed to occur in the formation of the dioxolanes: R , S ,- 2,2,4,5-tetramethyl-1,3-dioxolane, 7 and a mixture of R , R - and S , S -2,2,4,5-tetramethyl-1,3-dioxolane, 8 obtained from the reactions of acetone with R , R ,-/ S , S ,-buten-2-oxide and R , S ,-buten-2-oxide, respectively.

The synthesis and structural analysis of the new high nuclearity platinum-ruthenium cluster complex Pt2Ru8(CO)18(μ3−EtC2Et)2(μ4−EtC2Et) containing three alkyne ligands

AbstarctThe ten metal cluster complex Pt2Ru8(CO)23(µ3−H)2, 1 was found to react with EtC2Et to form a new ten metal tris-alkyne complex Pt2Ru8(CO)18(µ3−EtC2Et)2 (µ4−EtC2Et),2 in 35% yield. Complex 2 was characterized by IR,1H NMR , and single crystalx-ray diffraction analyses. The cluster can be viewed as a dodecahedron of eight metal atoms capped with two ruthenium carbonyl groups, two triply bridging EtC2Et ligands and one quadruply bridging EtC2Et ligand. Application of the standard electron counting procedures indicate that this is an unusual complex in which the 18 electron rule applies and the polyhedral skeletal electron pair theory does not. Crystal Data for 2 2.0.5 CH2CI2: space group = P21,a = 12.759(2) A,b=18.438(2)Å,c = 20.197(3) Å,β = 91.59(1)°, Z. = 4, 6394 reflections,R = 0.037.