Efficient Synthesis of Primary Amides from Carboxylic Acids Using N,N′-Carbonyldiimidazole and Ammonium Acetate in Ionic Liquid

A novel and efficient method for the conversion of carboxylic acids to primary amides using N,N′-carbonyldiimidazole in combination with ammonium acetate/triethyl amine system in [BMIM]BF₄ is developed.      

The Synthesis of Amide Dendritic Gelators and its Self-assembly Behavior in MMA

Three kinds of amide dendritic gelators, G₁-C₁₂-G₁, G₂-C₁₂-G₂ and gelator-1, were synthesized, and their self-assemble behavior in methyl methacrylate (MMA) was firstly investigated. The structures of the amide dendritic gelators were confirmed by ¹H-NMR and Mass spectra (MS). The gelation ability of the amide dendritic gelators was researched through tube inversion experiment, the results of which showed that different structures led to quite different gelation ability, including gel-sol temperature and critical concentration to form a stable gel. SEM experiments showed that three kinds of gelator formed different gel morphologies in MMA, all of which were nanoscale gel. All the three amide dendritic gelators could not only form stable gel network at certain temperature with different concentrations in MMA, but also in each case, an optically transparent gel was formed, which indicated dendrimers in the MMA had a good compatibility.     

<Emphasis Type="Italic">fac</Emphasis>-[Re(CO)<Subscript>3</Subscript>L] Complexes Containing Tridentate Monoanionic Ligands (L<Superscript>−</Superscript>) Having a Terminal Amido and Two Amine Ligating Groups

Abstract Treatment of fac-[Re(CO)₃(H₂O)₃]⁺ with two unsymmetrical tridentate NNN donor ligands (LH) based on a diethylenetriamine (dien) moiety with a 2,4,6-trimethylbenzoyl (tmbCO) group linked to a terminal nitrogen of dien through an amide produced the neutral complexes [Re(CO)₃(tmbCO-N,N-Me₂dien)] and [Re(CO)₃(tmbCO-dien)]. The [Re(CO)₃(tmbCO-N,N-Me₂dien)] complex crystallized in the space group P2₁/c, a = 19.5793 (15), b = 7.4239 (5), c = 14.8071 (10) ?, β = 104.425(5)°, V = 2084.4(3) ?³, and the [Re(CO)₃(tmbCO-dien)] complex crystallized in the space group C2/c, a = 36.861 (7), b = 7.3990 (10), c = 14.933 (3) ?, β = 102.145 (8)°, V = 3981.6(12) ?³. X-ray crystallographic and NMR analyses confirm that in both the solid and solution states the ligands are bound to the fac-Re(CO)₃ core in a tridentate fashion with the amide group being deprotonated. An important property in radiopharmaceuticals is shape, which in turn depends on ring pucker. For [Re(CO)₃(tmbCO-N,N-Me₂dien)], the two chelate rings have different pucker chirality, as is commonly found for a broad range of metal complexes. However, for fac-[Re(CO)₃(tmbCO-dien)], the two chelate rings have the same pucker chirality, a finding attributable to two strong intermolecular hydrogen bonds from the NH₂ to two waters of crystallization. Impeded by methyl group clashes with chelate ring hydrogens, the tmb ring rotation about the C(amido)–C(tmb) bond is slow on the NMR time scale. Index Abstract fac -[Re(CO) ₃ L] Complexes Containing Tridentate Monoanionic Ligands (L ⁻ ) Having a Terminal Amido and Two Amine Ligating Groups Anna Maria Chirstoforou, Patricia A. Marzilli, Frank R. Fronczek, and Luigi G. Marzilli X-ray crystallographic and NMR analyses of fac-Re(CO)₃ complexes containing diethylenetriamine-based, NNN tridentate ligands with a terminal deprotonated amido donor group allow comparison to previously reported analogues with a terminal deprotonated sulfonamido donor group. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.