Patrick Bauchat

Stereoselective, nonracemic synthesis of ω-borono-α-amino acids

Abstract ω-Unsaturated α-amino acids are synthesized through condensation of allyl and propargyl bromides or of 9-bromoundecene with a Ni(II) complex of the Schiff base derived from glycine and BPB. Hydroboration with Ipc 2 BH followed by oxidation with acetaldehyde affords enantiomerically pure ω-borono-α-aminocarboxylic acids.

Belokon's Ni(II) complex as a chiral masked glycine for the diastereoselective synthesis of 2-substituted 1-aminocyclopropane carboxylic acids☆

Abstract (1S,2R)- and (1R,2S)-Allonorcoronamic acids have been efficiently synthesised from the cyclic sulfate of 1,2-propanediol and Belokons complex (a complex of Ni(II) with glycine-(S)-2-[N′-(N-benzylprolyl)amino]benzophenone Schiff base ligands). The stereochemical outcome of the reaction was totally controlled by the sulfate partner.

Hydroboration of vinylglycine and allylglycine as a route to boron-derivatives of α-amino acids

Abstract The hydroboration of protected vinylglycine and allylglycine with dicyclohexyl- or diisopinocampheylborane occurs chimio- and regioselectively with attachment of boron to the less substituted end of the carbon-carbon double bond. Homoserine or δ-hydroxynorvaline are readily obtained by H 2 O 2 CH 3 CO 2 Na oxidation of dicyclohexylborane derivatives and 2-amino-4-boronobutanoic acid or 2-amino-5-boronopentanoic acid by reaction of diisopinocampheylborane derivatives with excess of ethanal and deprotection.

Synthesis and structural features of new [5,7] orthocyclophanes, [7,7] cyclophanes and corresponding macrobicyclic cryptophanes.

Abstract The Baylis-Hillman reaction of dialdehydes with methyl acrylate, followed by acetylation of the resulting diols gave diacetates 3, 14, 16 and 20. Treated with ammonia, these diacetates afforded new cyclophanes and the corresponding macrobicyclic cryptophanes. Conformational analysis of the cyclophanes was described.

Hydroboration of methyl 2-acetamidoacrylate. Characterisation and nucleophilic reactivity of the resulting oxytriorganoborate

Abstract Hydroboration of methyl 2-acetamidoacrylate with dicyclohexylborane places boron exclusively at the 2-position. The product is obtained as an internal complex whose zwitterionic structure is established by X-ray cristallography. Alkali metal salts of this heterocyclic oxytriorganoborate are readily alkylated or acylated.

HYDROBORATION OF METHYL 2-ACETAMIDOACRYLATE. II: NEW ASPECTS OF THE REACTIVITY OF THE RESULTING OXYTRIORGANOBORATES

Abstract The heterocyclic borate complex obtained by hydroboration of methyl 2-acetamidoacrylate acts as an ambident nucleophile, affording N- or C-alkyl or acylalaninates according to experimental conditions. Mechanistic hypotheses are proposed to rationalize these results.

Synthesis of New (4‐Acetonylidene‐2,6,8,9‐tetramethyl‐7H‐imidazo[1,5,4‐e,f][1,5]benzodiazepine) Derivatives

Abstract Imidazobenzodiazepine derivatives were obtained by cyclization of the condensation products 7‐amino‐2,5,6‐trimethylbenzimidazole with acetylacetone and ethyl acetoacetate. By careful examination of spectroscopic data and the open‐chain intermediate isolation, we have identified the formed compound structure.

Novel and Improved Method for the Synthesis of 2-mercaptobenzimidazole Derivatives

mercaptobenzimidazole derivatives were synthesized by reaction of o-phenylenediamines with N-aminorhodanine. This reaction represent a new synthesis of 2-mercaptobenzazole. The structure of the obtained products was established by spectroscopic data.