Mercaptopropyl-Modified Mesoporous Silica: Mercaptopropyl-Modified Mesoporous Silica: A Remarkable Support for the Preparation of A Remarkable Support for the Preparation of

a Reusable, Heterogeneous Palladium Catalyst foa Reusable, Heterogeneous Palladium Catalyst for Coupling Reactionsr Coupling Reactions

Cathleen M. Crudden,* Mutyala Sateesh, and Roxanne LewisCathleen M. Crudden,* Mutyala Sateesh, and Roxanne Lewis

J. Am. Chem. Soc. J. Am. Chem. Soc. 2005, 2005, 127, 127, 1004510045

Palladium-Catalyzed ReactionsPalladium-Catalyzed Reactions

Pdcatalyst

Heck-, Suzuki-,

C-C coupling : Hydrogenation Other reactions

H2

Diels-Alder, Oxidation etc

Suzuki-ReactionSuzuki-Reaction

R1 R2

BOH

OH X

Pd-catalyst

Base

R1

R2

Heck ReactionHeck Reaction

Z

X

R

Pd catalysts

Base

R

Z+

X=Cl, Br, IZ=COOR, Ph

X=Cl, Br, I

www.bgu.ac.il/mesoporous/ html/kinetics.htm

為何使用為何使用 SBA-15SBA-15 作為載體作為載體

具多孔性 高表面積 表面的 silanol 密度高，有利 (CH3O)3Si(CH2)3SH 與 silica 表面進行縮合反應

Pd(OAc)2 in THF Treated with Various Scavengers

Scavenging of Pd with SBA-15-SH and SiO2-SH

Suzuki-Miyaura Couplings with SBA-SH-Pd

Substrate Scope for the Suzuki-Miyaura Coupling

Reusability of the Catalyst in the Suzuki-Miyaura Reaction

SBA-15-Modified Pd Catalysts for the Mizoroki-Heck ReactionSBA-15-Modified Pd Catalysts for the Mizoroki-Heck Reaction

Hot Filtration Test

Three-Phase Test in the Suzuki-Miyaura Reaction

Conclusions

• Thiol-functionalized mesoporous silicates are efficient Pd scavengers and this materials have high ability of catalysis for Heck and Suzuki reaction.

• Several heterogeneity tests were indicate that the majority of the catalysis (>95%) occurs on the support via a truly heterogeneous catalyst.