A. Saporito

Metal complexes of 2-(o-hydroxyphenyl)pyridine

Abstract Complexes of 2-(o-hydroxyphenyl)pyridine (PhOHpy) with group VIIIB metal ions were synthesized and characterized by elemental analysis and spectroscopic measurements. The crystal and molecular structures of Co(PhOpy)3 and Pd(PhOpy)2 were determined. The Co complex crystallizes in the orthorhombic space group Fdd2, with a = 28.185- (14), b = 36.639(18), c = 12.639(18) A; Z = 16. The molecule has a mer-octahedral structure. Crystals of the Pd complex are orthorhombic, space group Pbca, with a = 17.140(3), b = 11.143(2), c = 9.488(2) A, Z = 4. The molecule is square-planar.

STABILIZATION OF UNSTABLE UNSATURATED MOLECULES IN FIVE-COORDINATE TBP COMPLEXES OF PT(II) : VINYL ALCOHOL DERIVATIVES

Abstract Vinyl alcohol has been stabilized in the equatorial position of trigonal bipyramidal Pt(II) complexes [PtX(Y) (dmphen) (CH2CHOH)] (X = Cl, Br, I; Y = Cl, Me; dmphen = 2,9-dimethyl-1,10-phenanthroline). The olefin can be functionalized by reactions with electrophiles, e.g. acetyl chloride and trichloroacetylisocyanate afford the corresponding complexes of vinyl acrylate and vinyl trichloroacetylcabamate, respectively. Alternatively, addition of KOH to [PtCl(Y) (dmphen) (CH2CHOH)] species yields the square-planar 2-oxoethyl products [Pt(Y) (CH2CHO) (dmphen)]. The X-ray crystal structure of [PtBrMe(dmpphen) (CH2CHOH)] discloses that the two olefic carbon atoms are symmetrically coordinated to the Pt atom.

A new effective method for the resolution of prochiral olefins : Stereoselective coordination in [PtCl3 (olefin)]− induced by crystallization

Crystallization of [PtCl3(olefin)]− [(S-C6H5CH(CH3)N(CH3)3]+ compounds (olefin = prochiral olefins) affords a single diastereoisomer through a second-order asymmetric transformation.

Regiospecific alkenylation of phenols by 1,1-dimethylallene promoted by platinum catalysts

1,1-Dimethylallene reacts with phenolic substrates in the presence of catalytic amounts of platinum(II) complexes. A regiospecific C-alkenylation takes place, affording o-isopentenylphenols and 2,2-dimethylchromans. Possible reaction mechanisms are also discussed.

Platinum complexes in organic synthesis: catalytic ortho-alkenylation of anilines

Anilines, 3-substituted with an ortho-para activating group, undergo, after protection of the amino group by acetylation, electrophilic addition with platinum(II)-co-ordinated 1,1-dimethylallene. This alkenylation is regiospecific, affording o-isopentenyl derivatives. A similar reaction is also observed with diphenylamine. A catalytic process is described.