Search

The preparation of new allylphosphonates and allylphosphoramidates bearing alkoxycarbonyl substituents is described. Both P-based precursors were subjected to RCM. In this context, several Ru-based catalysts were tested and compared in order to prepare new oxa- and aza-dihydrophosphinine oxides. P-heterocycles and homodimers have been obtained depending on the nature of the catalyst and the reaction conditions. In addition, homodimers were converted into six-membered cyclic phosphonates and phosphoramidates under Ru-promoted conditions.

An efficient method for the preparation of a novel family of functionalized phosphonomethyl α,β-unsaturated γ-lactams is established.

The Pd-catalyzed arylation of ester (II) followed by intramolecular cyclization of arylallylphosphonate intermediates affords the title compounds in a one-pot manner.

Michael addition of chiral β-enamino esters to MVK and acrylates promoted by Lewis acids (ZnCl 2 MgBr 2 ) or high pressure (11–14 Kbar) afforded, after hydrolytic work-up, α,α-disubstituted β-keto esters in good enantiomeric excesses.

β - enamino esters derived from β - keto esters and (S)-1- phenylethytamine, react with acrylonitrile in the presence of a Lewis acid or under high pressure activation to give, after hydrolytic work up, α,α- disubstituted β - keto esters 4 (EWG=CN) in enantiomeric excesses close lo 90%.

Reaction of ethyl chloroformate and acyl chlorides with iminoesters derived from 2- aminobenzimidazole, followed by Grignard reagent condensation leads to a variety of oxadiazinobenzimidazoles in good yield.

The reaction of N-thiocarbamoylimidates 1 with methyl thioglycolate leads to the formation of 4-arylamino-5-methoxycarbonylthiazoles 2. The condensation of the same imidates 1 on ethyl bromoacetate, benzyl bromide and chloroacetonitrile provides the corresponding 2-arylaminothiazoles 4.

The structure of KAuBr 4 , previously reported to be an isotype of KAuCl 4 , has been determined in the centrosymmetric space group P2 1 /c. The monoclinic cell contains four Au atoms (two Au1 and two Au2). The AuBr - 4 anions are nearly square planar, with Au1-Br bond lengths of 2.4096(15) and 2.4146(15) A, Au2-Br bond lengths of 2.4016(17) and 2.4172 (15) A, and Br-Au-Br angles of 90.31 (5) and 90.87 (6)° for Au1 and Au2, respectively.

The structure of K 2 PdBr 2.24 Cl 1.76 , dipotassium bromo-chloropalladate, an isotype of K 2 PdCl 4 and K 2 PdBr 4 , has been determined in the centrosymmetric space group P4/mmm. The tetragonal cell contains one Pd atom. The [PdX 4 ] 2- ions (X = Cl, Br) are square planar, with Pd-X bond lengths of 2.3934 (9) A.

Ammonium salts of β-functionalized allylic amines 1 were successfully employed as electrophilic agents with functional thiols. The obtained intermediate 2 underwent intramolecular cyclization in the presence of potassium tert-butoxide to afford 2,4-disubstituted tetrahydrothiophenes 3.