We present a new geometric interpretation of equivariant cohomology in which one replaces a smooth, complex G-variety X by its associated arc space J∞X, with its induced G-action. This not only allows us to obtain geometric classes in equivariant cohomology of arbitrarily high degree, but also provides more flexibility for equivariantly deforming classes and geometrically interpreting multiplic...

In the present study, a series of Mannich bases was synthesized by condensing 4,6-diacetylresorcinol with formaldehyde and some selected secondary amines following the Mannich reaction conditions. Findings revealed that Mannich reaction did not take place at the acetyl function but occurred on the aromatic ring position between the two hydroxyl groups. It was also observed that in one case inst...

A review of selected literature data related to intramolecular hydrogen bonding in ortho-hydroxyaryl Schiff bases, ortho-hydroxyaryl ketones, ortho-hydroxyaryl amides, proton sponges and ortho-hydroxyaryl Mannich bases is presented. The paper reports on the application of experimental spectroscopic measurements (IR and NMR) and quantum-mechanical calculations for investigations of the proton tr...

In an effort to develop anticancer agents, a series of Mannich bases were prepared by Mannich reaction. When one biologically active molecule is linked to another, the resultant molecule generally has increased potency. Hence two pharmacophores, i.e. quinazoline ring and amine moiety are fused to obtain highly potent, more specific and less toxic agent. In the present study, synthesis of novel ...

The amino alkylation of aromatic substrates by the Mannich reaction is of considerable importance for the synthesis and modification of biologically active compounds. The Mannich derivatives of 2-Chloro 4nitrobenzamide with formaldehyde and various secondary amines were synthesized for study of their biological effects. The structures of the synthesized compounds were assigned on the basis of e...

Here we describe our studies on solvent-dependent enantiodivergent Mannich-type reactions utilizing conformationally flexible guanidine/bisthiourea organocatalyst (S,S)-1. Our mechanistic investigations revealed that the stereo-determining steps in both the (R)- and (S)-selective Mannich-type reactions are governed by the cooperative effect of guanidine and thiourea in the inherently monomeric ...

For the first time, arylmethylidene cyclohexanones that are non-symmetrical due to the presence of peripheral substituents were studied in 1,3-dipolar cycloaddition reactions. It is shown that the interaction with the azomethine ylide generated from sarcosine proceeds regio- and diastereoselectively, with the participation of two non-equivalent parts of the dipolarophile. Also for the first tim...

In the title compound, C23H19NO2, an oxazine Mannich base derivative, the oxazine ring has a half-chair conformation. The 2-hy-droxy-naphthalen-1-yl substituent is placed in an axial position. There is an intra-molecular O-H⋯N hydrogen bond, forming an S(6) graph-set motif. In the crystal, mol-ecules are connected by a pair of C-H⋯π inter-actions into an inversion dimer, which is reinforced by ...

The title compound, C(23)H(23)NO, is the product of a tandem transformation of the double Mannich base bis-(1-oxo-1,2,3,4-tertrahydro-2-naphtho-ylmeth-yl)amine hydro-chloride in HBr solution upon heating. The tetra-hydro-pyridine ring has a non-symmetrical half-chair conformation, whereas the cyclo-hexa-diene and cyclo-hexene rings adopt non-symmetrical half-boat conformations. The dihedral ang...

Aminomethyl derivatives of 1,5-bis(4-hydroxy-3-methoxyphenyl)penta-1,4-dien-3-one, designed as new cytotoxins, were synthesized and evaluated in terms of their cytotoxic activities. The compounds have low CC50 values in the low micromolar range against HL-60 neoplasms and HSC-2, HSC-3 and HSC-4 carcinoma cells. In general, the average CC50 values of these compounds were higher towards HGF, HPC ...