Surface Decoration of Cellulose With Trifluoromethylphenyl Substituted Thiourea: A Robust Hydrogen-Bonding Catalyst in Conjunction With L-Proline for the Asymmetric Direct Mannich Reaction
Küçük Resim Yok
Tarih
2024
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Wiley
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Cellulose is one of the most abundant biopolymers in nature. Despite being the subject of research in various fields, it is not as famous as chitosan in catalyst design. Herein, a novel thiourea-functionalized cellulose (CTU-6) was synthesized as a robust hydrogen bonding catalyst with the degree of substitution (DS) of 0.84. CTU-6 was characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), x-ray powder diffraction (XRD), proton nuclear magnetic resonance spectroscopy (1HNMR), solid-state cross-polarization magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS 13C-NMR), thermal gravimetric analysis (TGA) and elementel analysis. CTU-6 catalyzed the direct asymmetric Mannich reaction between acetone, aniline, and various aromatic aldehydes in cooperation with L-proline. The reaction exhibited excellent enantioselectivity, achieving up to 98% enantiomeric excess (ee) at room temperature. Incorporating trifluoromethylphenyl-substituted thiourea into the cellulose framework leverages its ability to form hydrogen bonds, thereby enabling precise control over the asymmetric induction. This study highlights the potential of cellulose-based catalysts in advancing asymmetric synthesis and their versatility in various organic reactions in cooperation with small chiral ligands. This synergy not only facilitates the efficient catalytic process but also improves the stereochemical outcomes of the reactions. This method underscores the importance of utilizing renewable and versatile cellulose materials in combination with chiral auxiliaries to achieve high levels of enantioselectivity.
Açıklama
Anahtar Kelimeler
asymmetric Mannich reaction, cellulose, L-proline, organocatalysis, thiourea
Kaynak
Biopolymers
WoS Q Değeri
Q2
Scopus Q Değeri
Q2
Cilt
116
Sayı
1
