A mild and efficient method for the synthesis of vinylogous carbamates from alkyl azides

Highly Selective MOF-Based Turn-Off Luminescence Detection of Hg2+ Ions in an Aqueous Medium and Its Dual Functional Catalytic Activity toward Aldol Condensation and β-Enamination Reactions

A new organic ligand, 5-(carboxyformamido)isophthalic acid (5-CFIA), was prepared and employed for the synthesis of two compounds [M₃(C₁₀H₄O₇N₁)₂(8H₂O)]·H₂O (M = Cd, Mn). The compounds have three-dimensionally extended structures. Both the compounds were found to be luminescent at room temperature. The luminescence nature was exploited for the detection of Hg²⁺ ions in an aqueous medium with good selectivity. The interactions between Hg²⁺ ions and the compounds quench the luminescence intensity and act as a turn-off sensor. Both the compounds exhibited low limits for the detection of Hg²⁺ ions and in the range mandated by the WHO. The interactions between Hg²⁺ ions and the compound involve the -NH group, which was probed using Raman and IR spectroscopic techniques. These studies provide important pointers toward the mechanism of this turn-off luminescence behavior. The compounds were explored for base-catalyzed aldol condensation and Lewis acid-promoted β-enaminoester formation reactions. The aldol condensation reaction uses the -NH functionality as a base. The studies indicate that the electron-withdrawing group produces products with higher yields. The β-enaminoester reaction uses the Lewis acid centers, and the studies reveal that the electron-withdrawing groups produce lesser yields of the products. The catalytic nature of the reaction and recyclability of the catalysts were also established. The catalytic reactions employ ethanol (aldol condensation) and no solvent (β-enaminoester), which suggests that the reactions are green and environmentally friendly. The Mn compound was observed to be anti-ferromagnetic.

Triazinetriamine-derived porous organic polymer-supported copper nanoparticles (Cu-NPs@TzTa-POP): an efficient catalyst for the synthesis of N-methylated products via CO2 fixation and primary carbamates from alcohols and urea

Copper nanoparticles incorporated triazinetriamine derived porous organic polymer based catalyst was synthesized for catalytic production N-methylated amines and primary carbamates.

One-Pot Solvent-Free Three-Component Synthesis of Conjugated Enaminones Containing Three Alkyl Carboxylate Groups

An effective, one-pot, multicomponent, and solvent-free reaction for synthesis of conjugated enaminones containing three alkyl carboxylate groups is described. The reaction of primary amine, alkyl acetoacetate, and dialkyl acetylenedicarboxylate obtained the title compound in good yields in a short time.

(2Z,2′Z)-Diethyl 3,3′-[butane-1,4-diylbis(azanediyl)]bis(but-2-enoate)

The whole mol­ecule of the title β-enamino­ester, C₁₆H₂₈N₂O₄, is generated by a crystallographic inversion center, situated at the mid-point of the central C—C bond of the 1,4-diamino­butane segment. There are two intra­molecular N—H⋯O hydrogen bonds that generate S(6) ring motifs. This leads to the Z conformation about the C=C bonds [1.3756 (17) Å]. The mol­ecule is S-shaped with the planar central 1,4-diamino­butane segment [maximum deviation for non H-atoms = 0.0058 (13) Å] being inclined to the ethyl butyl­enonate fragment [C—C—O—C—C=C—C; maximum deviation = 0.0710 (12) Å] by 15.56 (10)°. In the crystal, mol­ecules are linked via C—H⋯O inter­actions, leading to the formation of an undulating two-dimensional network lying parallel to the bc plane.

A Facile Synthesis and Heteroannulation of Thiazolopyrimidine and Related Heterocyclic Systems

Reaction of pyrimidinylacetic acid 2 with different electrophilic and nucleophilic reagents gave annulated pyrimidine derivatives 3–11, respectively. Compound 3 ([7-(dibenzothien-2-yl)-5-phenyl-2,3-dihydro-5H-thiazolo[3,2-a]-pyrimidin-6-yl]acetic acid) was transformed to pyrimidinylacetyl azide 12, which upon heterocyclisation with active methylene compounds, acidic and basic reagents furnished functionally substituted heteroaromatic compounds 13–21, respectively. The structures of the synthesised derivatives were elucidated by elemental and spectral analyses.