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The η 3 -allenyl/propargyl complex [(PPh 3 ) 2 Pt(η 3 -CH 2 CCPh)]OTf ( 1 OTf) undergoes addition reactions with a number of oxygen nucleophiles in CH 2 Cl 2 solution at ambient temperature. With H 2 O, it yields the binuclear oxygen-bridged η 3 -allyl [{(PPh 3 ) 2 Pt(η 3 -CH 2 CCHPh)} 2 O](OTf) 2 ( 2 (OTf) 2 ). With primary and secondary alcohols, it rapidly affords the η 3 -(2-alkoxyallyl) complexes [(PPh 3 ) 2 Pt(η 3 -CH 2 C(OR)CHPh)]OTf (R=Et ( 3 OTf), i -Pr ( 4 OTf), CH 2 CMe 3 ( 5 OTf), CH 2 CHCH 2 ( 7 OTf)), whereas with tertiary alcohols, in slower reactions, it gives both 2 (OTf) 2 and [(PPh 3 ) 2 Pt(η 3 -CH 2 C(OR)CHPh)]OTf (R=CMe 3 , C(Me) 2 Et ( 6 OTf)). There is no reaction at ambient temperature between 1 OTf and phenols; however, 1 OTf and PhOH afford [(PPh 3 ) 2 Pt(η 3 -CH 2 C(OPh)CHPh)]OTf ( 8 OTf) in the presence of NEt 3 . Competition studies reveal the following reactivity order, attributed to steric effects: Me 3 CCH 2 OH(1.0) i -PrOH(1.2) 3 -(2-alkoxyallyl) complexes react with NaOMe to yield the η 3 -oxatrimethylemethane product (PPh 3 ) 2 Pt(η 3 -CH 2 C(O)CHPh) ( 10 ), which was also obtained by reaction of 2 (OTf) 2 with two equivalents of NaOMe and of 1 OTf with NaOH. Complex 10 undergoes conversion to the appropriate [(PPh 3 ) 2 Pt(η 3 -CH 2 C(OR)CHPh)] + with [Et 3 O]PF 6 , (MeO) 2 SO 2 and MeI. The η 3 -(2-allyloxyallyl) 7 OTf reacts with (PPh 3 ) 2 Pt(C 2 H 4 ) to give 10 and [(PPh 3 ) 2 Pt(η 3 -CH 2 CHCH 2 )]OTf; thermolysis of 7 OTf in toluene at reflux furnishes [(PPh 3 ) 2 Pt(η 3 -CH 2 CHCH 2 )]OTf, whereas heating in benzene–chloroform affords [(PPh 3 ) 2 Pt(η 3 -CH 2 C(OCHCHMe)CHPh)]OTf ( 11 OTf), which results from isomerization of OCH 2 CHCH 2 to OCHCHMe. Reaction pathways have been suggested for a number of the aforementioned transformations. All new complexes were characterized by a combination of elemental analysis, FAB mass spectrometry and 1 H-, 13 C{ 1 H}- and 31 P{ 1 H}-NMR spectroscopy. They were assigned structures in which the η 3 -allyl oxygen and Ph groups are syn from the 1 H-NMR spectra.

Dirhodium(II) catalysts possessing chiral pyrrolidone or oxazolidinone ligands provide moderate enantiocontrol (up to 80% ee) in carbon-hydrogen insertion reactions of N -alkyl- N -( tert -butyl)diazoacetamides; substituents at the 2-position of the N -alkyl group control regioselectivity for β- and γ-lactam formation.

Dirhodium(II) catalysts possessing chiral pyrrolidone or oxazolidinone ligands provide moderate enantiocontrol (up to 80% ee) in carbon-hydrogen insertion reactions of N -alkyl- N -( tert -butyl)diazoacetamides; substituents at the 2-position of the N -alkyl group control regioselectivity for β- and γ-lactam formation.

The stereoselective synthesis of two novel series of tribasic macrocyclic antibiotics with potent in vitro activity against Pasteurella multocida and Escherichia coli strains of bacteria is described. The in vitro activity can be significantly influenced by the nature of the substituents on the C-4" aminoalcohol, with the stereochemistry of the C-4" alcohol playing a less critical role. The effect of substitution and stereochemistry on the in vivo activity in a murine model of respiratory infection is also described.