Application of Pd Nanoparticles Supported on Mesoporous Hollow Silica Nanospheres for the Efficient and Selective Semihydrogenation of Alkynes

Abstract

Herein, the preparation of a heterogeneous catalyst consisting of 1–2 nm sized Pd nanoparticles supported on amino‐functionalized mesoporous hollow silica nanospheres and its use for the semihydrogenation of mono‐ and disubstituted alkynes is reported. By utilizing this Pd nanocatalyst together with the green poisoning agent DMSO, high yields of the desired alkenes could be achieved, while suppressing the degree of over‐reduction to alkanes. To our delight, the Pd nanocatalyst displayed remarkable chemoselectivity towards the alkyne moiety, allowing the transformation to be carried out in the presence of other reducible functionalities, such as halogens, carbonyl, and nitro groups.

Selective Semihydrogenation of Alkynes Catalyzed by Pd Nanoparticles Immobilized on Heteroatom‐Doped Hierarchical Porous Carbon Derived from Bamboo Shoots

“…This is a common method to address the trade off between activity and selectivity for Pd NPs in semihydrogenation, and can indeed effectively suppress the occurrence of over‐reduction even with reaction times prolonged after the point of full conversion (Figure S4). This is in good agreement with previous reports …”

“…Lipshutz and co‐workers developed an elegant Pd nanoparticle–nanomicelle combination system for the stereoselective hydrogenation of alkynes in water . Bäckvall and co‐workers reported supported Pd NPs on amino‐functionalized mesoporous hollow silica nanospheres for Z ‐selective semihydrogenation of alkynes . Sajiki and co‐workers developed a Pd/BN catalyst .…”

Manganese‐Mediated Aerobic Oxidative Olefination of (Het)Arenemethanols with Acetonitrile: Highly Stereoselective Preparation of Trans‐Cinnamonitrile Derivatives

“…Heck‐type reaction between a variety of benzene derivatives (such as arenes, haloarenes, aryl boric acid and acrylonitrile were proved to be an efficient method to prepare trans ‐cinnamonitriles (Scheme d) . Besides, selective semihydrogenation of 3‐phenylpropiolonitriles could also lead to the target trans ‐cinnamonitriles (Scheme e) . However, most of the raw materials of the above methods cost high and are not easily available.…”

Magnetic Fe3O4@SiO2/Pd and Fe3O4@SiO2/Pd‐M (M=Ag, Cu and Zn) Catalysts for Selective Hydrogenation of Phenylacetylene

“…The supports of palladium supported catalysts employed in phenylacetylene hydrogenation are various such as Al 2 O 3 , [3, 16] SiO 2, TiO 2 , carbon material and mixed oxide . In addition, graphitic carbon nitride and metal‐organic frameworks have been explored as potential supports.…”