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

• Published in: ChemCatChem 2016-02, Vol.8 (4), p.773-778
• Main Authors: Verho, Oscar, Zheng, Haoquan, Gustafson, Karl P. J., Nagendiran, Anuja, Zou, Xiaodong, Bäckvall, Jan-E.
• Format: Article
• Language: English
• Subjects: alkynes; heterogeneous catalysis; nanocatalysis; palladium; semihydrogenation
• ISSN: 1867-3880; 1867-3899; 1867-3899
• DOI: 10.1002/cctc.201501112

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. Avoiding over‐reduction: A heterogeneous catalyst comprised of Pd nanoparticles immobilized on aminopropyl‐functionalized hollow silica nanospheres (Pd0‐AmP‐HSN) has been synthesized and applied for the semihydrogenation of a variety of internal and terminal alkynes. By employing DMSO as a poisoning agent, a green and efficient catalytic system was achieved. This catalytic system shows an excellent selectivity towards the alkene products and tolerates the presence of other reducible functional groups.