G. Facchin

Novel cyclic «ylide-carbene» complexes. I: Synthesis of 3-(dimethylphenylphosphorane) indolidin-2-ylidene complexes of platinum(II) derived from metal-coordinated phosphonium-substituted isocyanide ligands

Nucleophilic attack of NEt3 on the activated methylene group of the -CH2P+R3 moiety of the platinum(II)-coordinated phosphonium-substituted isocyanides o-(X−+PR3CH2)C6H4NC (X = Cl, BF4 PR3 = PMe2Ph) produces the highly reactive ylide function -C−Hue5f8P+R3, which rapidly interacts intramolecularly with the metal-coordinated isocyanide group to form novel 5-membered cyclic ylide-substituted complexes of platinum(II) of the general formula LnPtII=CN(H)C6H4C(PMe2Ph) (LnPtII = cis-PtCl2PMe2Ph); trans-PtCl(PR′3)2+, PR′3 = PPh3, PMePh2, PMe2Ph).

Transition metal coordination and reactivity of 2-(azidomethyl)-, 2-(chloromethyl)- and 2-(iodomethyl)phenyl isocyanides

Abstract 2-(Azidomethyl)phenyl isocyanide, 2-(CH 2 N 3 )C 6 H 4 Nue606C (AziNC), coordinates to {M(CO) 5 } (M=W, Cr) fragments to afford the corresponding isocyanide complexes [M(CO) 5 (AziNC)] (M=W ( 1 ), Cr ( 2 )). AziNC coordinates also to some Au(I) species such as [AuCl(AziNC)] ( 3 ), derived from the reaction of [AuCl(Me 2 S)] with AziNC, and [Au(AziNC) 2 ][BF 4 ] ( 4 ), obtained from the reaction of 3 with AgBF 4 , followed by treatment with AziNC. Complexes 1 and 2 undergo the Staudinger reaction with PPh 3 affording the phosphinimine-isocyanide derivatives [M(CO) 5 {Cue606NC 6 H 4 -2-(CH 2 Nue605PPh 3 )}] (M=W ( 5 ), Cr ( 6 )). Complex 6 reacts with H 2 O affording a mixture of the amino–isocyanide [Cr(CO) 5 {Cue606NC 6 H 4 -2-(CH 2 NH 2 )}] ( 7 ) and the carbene [Cr(CO) 5 { CN(H)C 6 H 4 -2-CH 2 N (H)}] ( 8 ) species. Complexes 3 and 4 react with 1 or 2 equiv. of PPh 3 displacing the isocyanide with the formation of the complexes [AuCl(PPh 3 )] ( 9 ) and [Au(PPh 3 ) 2 ][BF 4 ] ( 10 ), respectively. The halogeno–isocyanide complexes [W(CO) 5 (CNC 6 H 4 -2-CH 2 Cl)] ( 11 ) and [W(CO) 5 (CNC 6 H 4 -2-CH 2 I)] ( 12 ) show different reactivity towards amines so that only 12 reacts with MeNH 2 to afford in low yield the N -heterocyclic carbene species [W(CO) 5 { CN(H)C 6 H 4 -2-CH 2 N (Me)}] ( 13 ).

The lysine glycation 1. A preliminary investigation on the products arising from the reaction of protected lysine and D-glucose.

SummaryThe nature of the products arising from a 10 days, sterile incubation at 37°C and pH 7.2 of a 1:1 mixture of N-α-(p-tosyl)-lysine-methylesterhydrochloride and anhydrous D-glucose was investigated by fast atom bombardment mass spectrometry and1H and13C nuclear magnetic resonance spectroscopies. Differently to the reactivity usually described on the basis of other analytical techniques, FAB mass spectrometric measurements indicate the occurrence of the reaction of protected lysine with more than one D-glucose molecule.