Silica-Supported Cationic Gold(I) Complexes as Heterogeneous Catalysts for Regio- and Enantioselective Lactonization Reactions

Transcription

1 Silica-Supported Cationic Gold(I) Complexes as Heterogeneous Catalysts for Regio- and Enantioselective Lactonization Reactions Xing-Zhong Shu, Son C. Nguyen,Ying He, Fadekemi Oba, Qiao Zhang, Christian Canlas, Gabor A. Somorjai, A. Paul Alivisatos, and F. Dean Toste J. Am. Chem. Soc. 2015, 137, Literature Seminar Pauline Rullière 11 Novembre 2015

2 The Dean Toste group Asymmetric Chiral Anion Catalysis TORONTO B.Sc. MAJOR STANFORD PhD TROST 2000 POSTDOC GRUBBS CaLTeCH 2002 ASSISTANT 2009 BERKELEY FULL PROFESSOR Supramolecular Cluster Chemistry Toste, F. D. et al. J. Am. Chem. Soc. 2015, 137,

3 The Dean Toste group Asymmetric Chiral Anion Catalysis TORONTO B.Sc. MAJOR STANFORD PhD TROST 2000 POSTDOC GRUBBS CaLTeCH 2002 ASSISTANT 2009 BERKELEY FULL PROFESSOR Palladium Catalysis and Reactivity Supramolecular Cluster Chemistry Toste, F. D. et al. J. Am. Chem. Soc. 2014, 136,

4 The Dean Toste group Asymmetric Chiral Anion Catalysis TORONTO B.Sc. MAJOR STANFORD PhD TROST 2000 POSTDOC GRUBBS CaLTeCH 2002 ASSISTANT 2009 BERKELEY FULL PROFESSOR Gold Catalysis and Reactivity Palladium Catalysis and Reactivity Supramolecular Cluster Chemistry Toste, F. D. et al. J. Am. Chem. Soc. 2014, 136,

5 Pauline Rullière 11 Novembre 2015

6 Synergistic catalysis on a solid surface A good way to integrate both heterogeneous and homogeneous catalysis Easy to tune the catalyst heterogeneous vs homogeneous catalysis - asymmetric reactions + + sustainability - + industrial processes - + spatial positioning - How to heterogenize homogeneous catalysts? - encapsulation of the catalyst - sustainability of the catalytic system - encapsulating polymer as a cocatalyst - surface mediated design Gross, E.; Toste, F. D.; Somorjai, G. A. Catal. Lett. 2014, 145, 126. Tada, M.; Motokura, K.; Iwasawa, Y. Top Catal 2008, 48, 32. 6

7 Homogeneous synergistic catalysis Chiral ureas in asymmetric cooperative catalysis of acid-promoted Povarov reaction Cooperative bimetallic catalysis - conjugate addition of malonates (La and Na) - aza-henry reaction (Yb and K) - direct aldol reaction (La and Li) Xu, H.; Zuend, S. J.; Woll, M. G.; Tao, Y.; Jacobsen, E. N. Science 2010, 327, 986. Matsunaga, S.; Shibasaki, M. Chem. Commun. 2014, 50,

8 Synergistic catalysis on a solid surface A good way to integrate both heterogeneous and homogeneous catalysis Tuneable catalysis Cooperative action of : acid base acid thiol amine urea imidazole alcohol carboxylate Davis, M. E. et al. Chem. Soc. Rev. 2008, 37, Yu, C.; He, J. Chem. Commun. 2012, 48,

9 Synergistic catalysis on a solid surface A good way to integrate both heterogeneous and homogeneous catalysis Tuneable catalysis Imprints design Davis, M. E. et al. Chem. Soc. Rev. 2008, 37, Yu, C.; He, J. Chem. Commun. 2012, 48,

10 Immobilized synergistic catalysts : previous work Acid-base catalysis Motokura; Tada, M.; Iwasawa, Y. J. Am. Chem. Soc. 2007, 129,

11 Immobilized synergistic catalysts : previous work Acid-base catalysis With transition metal Noda, H.; Motokura, K.; Miyaji, A.; Baba, T. Angew. Chem. Int. Ed. 2012, 51,

12 Immobilized synergistic catalysts : previous work Acid-base catalysis With transition metal catalyst yield Pd complex 0 Pd complex + tertiary amine 0 SiO 2 /diamine/pd/net 2 96 SiO 2 /diamine/pd 26 SiO 2 /diamine/net 2 0 SiO 2 /diamine/pd + tertiary amine 6 SiO 2 /diamine/pd + SiO 2 /NEt 2 28 Noda, H.; Motokura, K.; Miyaji, A.; Baba, T. Angew. Chem. Int. Ed. 2012, 51,

13 Synthesis of the silica-supported catalyst 13

14 Synthesis of the silica-supported catalyst 14

15 Integrity of the adsorbed catalyst Au réf 15

16 Integrity of the adsorbed catalyst Au free BF 4 - Si-OH bonded BF 4 - free BF 4 - bulk BF 4-19 F NMR of Ph 3 PAuBF 4 in solution (MeCN) 19 F solid state NMR of SBA-15@Ph 3 PAuBF 4 16

17 Cationic metal complexes adsorbed through counter-anion bonding Non-covalent immobilization of homogeneous cationic rhodium Rege, F. M. de; Morita, D. K.; Ott, K. C.; Tumas, W.; Broene, R. D. Chem. Commun. 2000, Bianchini, C.; Burnaby, D. G.; Evans, J.; Frediani, P.; Meli, A.; Oberhauser, W.; Psaro, R.; Sordelli, L.; Vizza, F. J. Am. Chem. Soc. 1999, 121,

18 Integrity of the adsorbed catalyst 18

19 Improved lactonizations SBA-15 PPh 3 AuBF 3 AuBF 4 Subtrate time (min) yield time (min) yield efficiency (protodeauration) -> proximity of acid - regioselectivity -> bulkiness of supported catalyst 19

20 Mechanism Brown, T. J.; Weber, D.; Gagné, M. R.; Widenhoefer, R. A. J. Am. Chem. Soc. 2012, 134,

21 Enhanced regioselectivity - efficiency (protodeauration) -> proximity of acid - regioselectivity -> bulkiness of supported catalyst 21

22 Application to enantioselective nucleophilic addition to allenes Precedent in literature Lipshutz, B. H. et al. Angew. Chem. Int. Ed. 2014, 53,

23 Application to enantioselective nucleophilic addition to allenes Reasons for such a selectivity : confinement +/- dual catalysis

24 Sustainable chemistry?...catalyst recycling & recovery After 11 runs : 63% of molecular Ph 3 PAuBF 4 (FTIR) 3.2 % of leaching (ICP-OES) Presence of nanoparticles => Reduction to Au(0) 24

25 Perspectives and openings one-step synthesis from the homogeneous catalyst and it retains the tunable electronic and steric properties of the original molecular catalyst Improvement of support-catalyst strength => how to reduce leaching? Slow development of heterogeneous asymmetric catalysis Feasibility of chiral catalyst tuning Molecular control of solid matrix 25

26 Acknowledgement 26