Hassan Aït-Haddou

ENAMINONES IN THE SYNTHESIS OF NEW POLYAZA HETEROCYCLES

A simple and efficient method for the synthesis of larger polyaza heterocyclic structures 6a, 6b and 8 with 1,3-pyrimidine units has been developed, based on the reaction of enaminones with appropriate guanidines or carboxamidines under basic conditions. Using this procedure, several new, optically active polyaza heterocycles 10, 12 and 13 have been prepared in good yields, from enantiomerically pure Nα-Boc-L-arginine as guanidine reagents.

NEW HOMOCHIRAL BIS(OXAZOLINE) LIGANDS FOR ASYMMETRIC CATALYSIS

Abstract Several homochiral bis(oxazolines), with asymmetric centers on the oxazoline rings and on the side chains, were prepared from (1S,2S)-(+)-2-amino-1-phenyl-1,3-propanediol in high yields. Asymmetric cyclopropanation of styrene with ethyl diazoacetate in the presence of 1 mol% of copper( I ) triflate and the dibenzoyl bis(oxazoline) 5a . gave ethyl 2-phenylcyclopropanecarboxylate in up to 85% ee. The same ligand 5a , was used in the palladium catalysed enantioselective allylic substitution of the 1,3-diphenyl-2-propenyl acetate to give the desired product in up to 90% ee.

The Reaction of Enaminones with Grignard Reagents: Synthesis of α,β-Unsaturated Ketones

Abstract Enaminones in toluene react with Grignard reagents in tetrahydrofuran at 0–25 °C, to give selectively and with high yields the corresponding α,β-unsaturated ketones.

Synthesis of Highly Soluble Annelated Polypyridines

Highly soluble annelated bi- and terpyridines were prepared in 46–60% yields by a two-step procedure which combines the Michael addition of an enolizable cyclic ketone with an α,β-unsaturated ketone and the cyclization of the resulting 1,5-diketone in the presence of ammonium acetate.

New annelated 2,2′:6′,2′′-terpyridines and their Ru(II) complexes: synthesis and characterisation

Abstract Two annealed terpyridine ligands have been prepared in which the substituted groups are located on the 4,4′′,5,5′′ positions. The corresponding homoleptic ruthenium(II) complexes were obtained in excellent yields, one of which was analysed by X-ray crystallography.

Synthesis of Dicyanopyridines

Abstract Synthesis of the title compounds in four steps using inexpensive collidine and lutidine as starting materials is described.

Synthesis of New Soluble Annelated Polypyridines

A new octahydroacridine with a tert-butoxypropyl group in the 9-position was prepared and was used in the synthesis of new soluble annelated polypyridines. Quinquepyridine with 11 adjacent rings was prepared in 17-25% yield by condensation of an α-methylene ketone and an enolisable ketone in the presence of ammonium acetate under basic conditions.

New ruthenium( II ) heteroleptic complexes containing the 4-(2-pyridyl)pyrimidine ligand with amine and amino acid substituents

New 4-(2-pyridyl)pyrimidines (L) have been synthesized in high yields by condensing enaminones with the appropriate carboxamidine or guanidine under basic conditions. These asymmetric bidentate diimine ligands coming from a one-step functionalization of amine and amino acid groups were complexed to ruthenium to obtain new heteroleptic complexes of type [Ru(bpy)2(L)]2+. The ligands and complexes have been characterized by usual analytical methods, and the crystallographic study of one complex has been performed. Their spectroscopic and electrochemical properties have been investigated. ZINDO Calculations show that in the MLCT excited state the electron is mainly localized on the pyridylpyrimidine ligand. On the basis of electrochemical data, the first reduction potential of the complexes has been assigned to the redox couple involving this ligand.