Nanohybrid mate asymmetric reactions with pote asymmetric reactions with pote R. A. Miranda, F. Medina, R. A. Miranda, F. Medina, Departament d’Enginyeria Química, Universitat Rovira Research Center on Engineering of Materials and Micro/nano Sistems, Research Center on Engineering of Materials and Micro/nano Sistems, *E-mail: anama Antecedents Recently, nanohybrid materials received considerable interest due to their wide number of applications in nanoscience and catalysis. They often exhibit extraordinary high synergetic and complementary behaviour between two nia nia Antecedents extraordinary high synergetic and complementary behaviour between two component materials. In particular, the combination of hydrotalcite-like materials (HTs) and chiral molecules such as aminoacids (AA) and poly-aminoacids (PAA) offer new areas for developing hybrids with the desired functionality [1], as well as gèn gèn offer new areas for developing hybrids with the desired functionality [1], as well as these materials are able to catalyze the synthesis of chiral drugs [2]. Some examples of organic-inorganic nanohybrid materials based on AA and HTs used as catalysts have been reported. However, in all cases the synthesis time of the erog erog catalysts have been reported. However, in all cases the synthesis time of the material is higher than 24 hours. And, to the best of our knowledge, there is any in- depth study of the interaction between the AA or PAA and HTs [3]. Hete Hete Results an si H si H Results an Synthesis and characterization of nanohybrid materials tàlis tàlis Synthesis and characterization of nanohybrid materials Chiral molecules Method A 30 min. at r.t. magnetic stirring L-Leu/HTA 0.44 (AA) Cat Cat magnetic stirring L-Pro/HTA 0.44 L-Leu/HTB 1.09 Method B 180 min. at 353 K magnetic stirring L-Leu L-Pro or (AA) COOH NH 2 OH O en en L-Leu/HTB 1.09 L-Pro/HTB 1.02 magnetic stirring L-Pro 30 min. at r.t. magnetic stirring PLLc/HT (PAA) N H COOH O O ió e ió e [Mg 2 Al(OH) 7 ]·mH 2 O magnetic stirring PLLc/HT (0.08 mg PLLc/mg HT) PLLs/HT (0.30 mg PLLs/mg HT) PLLc PLLs or H H N OH O n H 2 N N H O H N O H N O N H O NH 2 n m gaci gaci Fig.1. Methods of immobilization of AA and PAA onto rehydrated HT. AA amount was calculated using TOC analysis. PAA amount was calculated using TGA. stig stig HRTEM 7.7 Å 7.7 Å L-Leu/HTA PLLc/HT XRD nves nves ♦ ♦ HT ♦ 19.3 Å 7.7 Å 19.3 Å 7.7 Å L-Leu/HTA 0.44 PLLc/HT d d´in in L-Leu/HTA 0.44 14.7 Å L-Pro/HTA 0.44 L-Pro/HTB 1.02 14.7 Å L-Leu/HTB up up L-Leu/HTB 1.09 11.6 Å PLLc/HT 0.08mg PLLs/HT 0.30mg 11.6 Å L-Leu/HTB 1.09 PLLs/HT Gru Gru 2-θ 4 10 20 30 40 50 60 70 ♦ Basal peaks of (003) and (006) of HT. Basal peaks of planes (003), (006) and (009) of the HT with chiral molecule intercalated. Basal peak of L-Leu. 0.30mg – MAS-NMR and FT -IR Fig. 2. HRTEM and XRD analysis of the synthesized nanohybrid material. gili gili MAS-NMR and FT -IR O(H) H α β γ δ H 2 N C α C β C γ C δ H 3 H Virg Virg Material 13 C MAS-NMR (ppm) FT-IR (cm -1 ) N H O α γ 2 α β H 2 γ H C δ H 3 COO(H) a i a i Material (ppm) (cm -1 ) COO(H) C α C β C γ C δ ν asCOO(H) L-Leu 176 55 44 27 24 1581 L-Leu/HTA 185 58 47 27 24 1560 ovira ovira L-Leu/HTA 0.44 185 58 47 27 24 1560 L-Leu/HTB 1.09 185 59 46 26 16 1560 L-Pro 178 65 49 36 28 1624 L-Pro/HTA 185 67 50 34 28 1624 + 1570 Ro Ro Table 1. 13C MAS-NMR and FT-IR frequencies of asymmetric vibrations of carboxylic group of free and immobilized AA . L-Pro/HTA 0.44 185 67 50 34 28 1624 + 1570 L-Pro/HTB 1.02 185 66 50 35 28 1570 tat tat Nature of the biohybrid materials ersit ersit nive nive Un Un L-leu/HT-A L-Leu/HTA L-Leu/HTB PLL/HT Acknowledgements: We thank MCI from Spain and URV for the economical support, Dr. J. Llorca (Universitat Politècnica de Catalunya) for performing the HRTEM experiments, and Drs. G. Ramis and E. Finocchio (Genoa University) for helpful discussions about the FTIR experiments. R.-A.M. thanks to URV for his predoctoral fellowship. F . Medina thanks to Gencat for the ICREA ACADEMIA thanks to URV for his predoctoral fellowship. F . Medina thanks to Gencat for the ICREA ACADEMIA award. References: [1] U. Costantino, V. Ambrogi, M. Nocchetti, L. Perioli. Micropor. Mesopor. Mater. 107, 149 (2008). [2] C.Lauret, and S. Roberts. AldrichimicaActa. 35, 47 (2002) and references there in. [3] B.M. Chaudary, B. Kavita, N. Sreenivasa Chowdary, B. Sreedhar, M. Lakshmi Katam. J. Catal. letter, B.M. Chaudary, B. Kavita, N. Sreenivasa Chowdary, B. Sreedhar, M. Lakshmi Katam. J. Catal. letter, 78, 373 (2001); S. Vijaikumar, A. Dhakshinamoorthy, K. Pitchumani, Applied Catalysis A: General 340, 25 (2008). erials as catalysts of ential pharmaceutical applications ential pharmaceutical applications J.E. Sueiras and A.M. Segarra* J.E. Sueiras and A.M. Segarra* a i Virgili, Tarragona, Av. Països Catalans, 26, 43007, Spain , Universitat Rovira i Virgili, Tarragona, Marcel-li Domingo, s/n, 43007, Spain , Universitat Rovira i Virgili, Tarragona, Marcel-li Domingo, s/n, 43007, Spain [email protected] Our project The aim of this work is the design of different novel biohybrid nanomaterials based on L-Leucine (L-Leu), L-Proline (L-Pro) and Poly-L-Leucine (PAA) immobilized onto HTs. These materials have been used as catalysts for the Aldol asymmetric reactions Our project HTs. These materials have been used as catalysts for the Aldol asymmetric reactions and the asymmetric epoxidation of α,β-unsaturated ketones. Some of the obtained products are precursors of Naproxen (anti-inflammatory), Taxol (cancer chemotherapy), Stantin (lower cholesterol levels), or (+)-fenoprofen (rheumatoid chemotherapy), Stantin (lower cholesterol levels), or (+)-fenoprofen (rheumatoid arthritis). The nature of the resulting biohybrid materials and the interactions between their components were characterized by TOC, XRD, HRTEM, FT-IR, 13 C and 13 Al NMR-MAS, MALDI and ESI-TOF mass spectroscopy . nd Discussion NMR-MAS, MALDI and ESI-TOF mass spectroscopy . nd Discussion Study of asymmetric reactions Asymmetric epoxidation reaction of chalcone Study of asymmetric reactions O O O O O Ph O Ph Ph O Ph O Ph O Ph O Ph O Ph O Ph O Ph O Catalyst NaOH, H 2 O 2 , TBAB THF, 1.5h, rt + + + (R,R)-cis Chalcone (R,S)-trans (S,R)-trans (S,S)-cis (R,R)-cis (R,R) (S,S) L-Leu 1 L-Leu/HTB 1.09 1 Catalyst HT 1 L-Leu/HTA 0.44 1 PLLc/HT 2 PLLc 2 PLLs/HT 2 PLLs 2 1 Reaction conditions: 1.44 mmol chalcone, 1.5 equiv. NaOH 2M, 1.5 equiv. H 2 O 2 (30% wt), 0.042 mmol TBAB, 3 mL Hexane, catalyst with an L-Leu content of 18 mg, 3h, rt. The ee was determined by chiral HPLC analysis (Chiralpak IA). The conversion was determined by 1 H NMR (Varian 400MHZ). 400MHZ). 2 Reaction conditions: 0.24 mmol chalcone, 10 equiv. NaOH 5M, 11.9 equiv. H 2 O 2 (30% wt), 0.024 mmol TBAB, 1 mL Toluene, 200%w PLL, 1h, rt. The ee was determined by chiral HPLC analysis and the conversion was determined by 1 H NMR. Direct asymmetric aldol reaction NO H O O THF, rt O OH + Catalyst O OH + NO 2 NO 2 NO 2 (R)-Enantiomer (S)-Enantiomer (R,R) (S,S) HT Catalyst L-Pro/HTA 0.44 R L-Leu/HTB 1.02 Catalyst L-Pro 0.44 S Reaction conditions: 0.1 mmol L-Pro, 13.6 mmol acetone, 0.5 mmol aldehyde, 2 mL THF, 24h, rt. The ee was determined by chiral HPLC analysis (Chiralpak IA). The conversion was determined by 1 H NMR (Varian 400MHZ). (Chiralpak IA). The conversion was determined by 1 H NMR (Varian 400MHZ). Conclusions Two different biohybrid materials based on AA into a hydrotalcite rehydrated under ultrasounds were synthesized using efficient and easy protocols. Method A: AA immobilized by replacing hydroxyl ions at the edges of HT . Method B: AA immobilized by intercalation. the edges of HT . Method B: AA immobilized by intercalation. The AA immobilized in the interlayer spacing of HT (method B), presented enantioselectivity in the aldol and J-C epoxidation reactions. The L-Pro/HTB nanohybrid achieved different catalytic behavior for the direct aldol reaction than pure L- The L-Leu/HTA presented high activity towards the trans-epoxide. The L-Pro/HTB nanohybrid achieved different catalytic behavior for the direct aldol reaction than pure L- Pro, showing moderate conversions with inversion of the enantioselectivity. The PLLs/HT presented similar activity and selectivity than the PLLc/HT. The PLLs/HT was recycled and reused during 5 consecutive runs (Results not showed). reused during 5 consecutive runs (Results not showed).