Owing to their superior mechanical performance, strong adhesion, thermal resistance, and insulating properties, epoxy resins are commonly employed as protective coatings, electronic encapsulants, adhesives, and matrices in composites. The selection of the epoxy system components—the base resin and curing agent—along with the chosen curing protocol, directly determines the properties of the final cross-linked polymer. This study compares the influence of halogen substituents in 4,4′-methylenebis(2,6-diethylaniline) (MDEA), 4,4′-methylenebis(3-chloro-2,6-diethylaniline) (MCDEA) and 4,4′-methylenebis(3-bromo-2,6-diethylaniline) (MBDEA). The results of mechanical tests on plastics and composites demonstrated an increase in the strength properties and elastic modulus of the matrix, improved adhesive interactions with carbon fiber, and showed a reduction in moisture saturation across the series MDEA → MCDEA → MBDEA. Notably, the improvement in properties exceeded the increase in the density of the compositions, indicating an enhancement in the specific characteristics of the matrix.

Acetophenone-derived bis-Mannich bases, known for their bioactivity and potential to act as Michael acceptors via deamination and acrolein-type release, have historically suffered from low-yielding syntheses due to their instability. We report a simple, high-yielding (80–90% in most cases), scalable method using TMMDA and ZnCl₂ that eliminates the need for chromatographic purification. Mechanistic and DFT studies revealed that TMMDA functions as both a base and iminium precursor, while ZnCl₂ promotes acetophenone enolization and stabilizes the products. Notably, these bis-Mannich bases exhibit unprecedented reactivity with N-nucleophiles in aqueous media, forming hexahydro-pyrimidine and diazabicyclo[3.2.1]octane scaffolds. This transformation was successfully applied in the late-stage func-tionalization of erlotinib, including conjugation with the αvβ3-targeting cyclo(RGDfK) peptide. In vitro studies revealed enhanced nonspecific antiproliferative activity for erlotinib derivatives, likely driven by deamination and subsequent Michael addition to abundant nucleophiles in biomolecules. Overall, this work reestablishes bis-Mannich bases as versatile intermediates for heterocycle synthesis and drug modification.

Acetophenone-derived bis-Mannich bases, known for their bioactivity and potential to act as Michael acceptors via deamination and acrolein-type release, have historically suffered from low-yielding syntheses due to their instability. We report a simple, high-yielding (80–90% in most cases), scalable method using TMMDA and ZnCl₂ that eliminates the need for chromatographic purification. Mechanistic and DFT studies revealed that TMMDA functions as both a base and iminium precursor, while ZnCl₂ promotes acetophenone enolization and stabilizes the products. Notably, these bis-Mannich bases exhibit unprecedented reactivity with N-nucleophiles in aqueous media, forming hexahydropyrimidine and diazabicyclo[3.2.1]octane scaffolds. This transformation was successfully applied in the late-stage functionalization of erlotinib, including conjugation with the α_vβ₃-targeting cyclo(RGDfK) peptide. In vitro studies revealed enhanced nonspecific antiproliferative activity for erlotinib derivatives, likely driven by deamination and subsequent Michael addition to abundant nucleophiles in biomolecules. Overall, this work reestablishes bis-Mannich bases as versatile substrates for heterocycle synthesis and drug modification.

The application of high-temperature bismaleimide resins in structural composites is inherently limited by the trade-off between thermal performance and processability. Here, we report a targeted molecular design strategy to overcome this operational bottleneck. By introducing bulky ortho-ethyl substituents into a monomeric architecture, premature homopolymerization was selectively suppressed up to 300 °C while maintaining the rigidity of the aromatic backbone. The resulting resin system provides an optimized processing profile for vacuum-assisted resin transfer molding (VARTM), characterized by low melt viscosity (<400 mPa·s) across a 120–140 °C range and isothermal stability exceeding 8 h. The fabricated carbon fiber reinforced polymer (CFRP) exhibits a high glass transition temperature (up to 277 °C) and retains 92.5% of its room-temperature flexural modulus at 250 °C (49 GPa). This strategy serves as a technological basis for the autoclave-free manufacturing of heat-resistant structural materials.