Demetrius Michos

Alkyl hydroperoxide oxidation of alkanes and alkenes with a highly active Mn catalyst.

The system ROOH/[Mn3O4(dipy)4(OH2)2](ClO4)4 hydroxylates alkanes and converts ArCRCH2 to ArCRO with extremely high activity and good conversions and yields.

Colloidal palladium, easily formed in organic solvents, is a highly active and stable catalyst for selective hydrogenations and dehydrohalogenations

Abstract Collidal Pd formed in organic solvents from Pd(hfacac)2 and silane or an Si-H- containing polymer is an active, stable and selective catalyst for hydrogenation and dehydrohalogenation.

Synthesis and characterization of some rhenium complexes with the new mixed phosphorus–nitrogen donor ligand NPh(CH2CH2PPh2)2

Reaction of NPh(CH2CH2Cl)2 with LiPPh2 at 0 °C yields the new mixed nitrogen–phosphorus donor ligand NPh(CH2CH2PPh2)2(L). Reaction of [ReOCl3(AsPh3)2] with L in CH2Cl2 at room temperature gives [ReOCl3L]3. Reaction of [ReCl3(MeCN)(PPh3)2] with L in refluxing benzene gives [ReCl3L]4. Treatment of 3 or 4 with LiAlH4 at 0 °C in Et2O affords [ReH5L]5. Protonation of 5 with HBF4·OEt2 in CD2Cl2 at 193 K gives [ReH6L]+6. Deprotonation of 6 with NEt3 regenerates 5 quantitatively. Compound 5 shows a 1H NMR T1(minimum) value of 78 ms at 250 MHz, consistent with a classical structure having only terminal hydride ligands, while 6 shows a T1(minimum) value of 10 ms, suggesting a non-classical structure containing one or more η2-H2 ligands.

Synthesis and characterization of some new complexes of the Vaska-type trans-[IrX(CO)L2] (XCl or I; L=phosphite, phosphinite or phosphonite) and the direction of dihydrogen addition to these species

Abstract A series of new Vaska-type complexes trans -[IrX(CO)L 2 ] (XCl, LP(OEt)Ph 2 ( 1 ), P(OEt) 2 Ph ( 2 ), P(O- o -C 6 H 4 Ph) 3 ( 3 ), P(OPr i ) 3 ( 4 ), P(OBu n ) 3 ( 5 ); XI, LP(OEt)Ph 2 ( 6 ), P(OEt) 2 Ph ( 7 ), P(O- o -C 6 H 4 Ph) 3 ( 8 ), P(OBu n ) 3 ( 9 ) are prepared and characterized. In solution complex 8 undergoes slow cyclometallation to give [IrHI(CO){P(O- o -C 6 H 3 Ph)(O- o -C 6 H 4 Ph) 2 } {P(O- o -C 6 H 4 Ph) 3 }] ( 10 ). The oxidative addition of H 2 to 1–9 occurs stereospecifically with cis addition of H 2 parallel to the XIrCO axis rather than perpendicular to the axis, leading to cis , trans -[IrH 2 X(CO)L 2 ] with a trans disposition of the two L ligands. This direction of H 2 addition is not in agreement with a prior suggestion based on ab initio quantum chemical calculations.