Holz J,
Pfeffer C,
Zuo H,
Beierlein D,
Richter G,
Klemm E,
Peters R.
* Universität Stuttgart and MPI IS Stuttgart, Germany
In Situ Generated Gold Nanoparticles on Active Carbon as Reusable Highly Efficient Catalysts for a C(sp
3)–C(sp
3) Stille Coupling.
Angew. Chem. Int. Ed. 2019;
58: 10330-10334
Key words
gold catalysis - nanoparticles - Stille coupling - benzyl halides - allylstannanes - dienes
Significance
Activated-carbon-adsorbed gold nanoparticles formed in situ catalyzed the C(sp3)–C(sp3) coupling reaction of benzylic bromides with allyl(tributyl)stannanes to give the corresponding homoallylic benzenes in up to >99% yield (eq.1). This catalyst was also applicable on an allyl–allyl coupling reaction to furnish 1,5-dienes in yields of 54–59% (eq. 2).
Comment
The coupling of (2-bromoethyl)benzene with allyl(tributyl)stannane proceeded in the presence of a 0.001 mol% loading of the gold nanoparticles to give the coupling product in 29% yield with a total turnover number of up to 29000. The catalyst was recovered by centrifugation and recycled four times without a loss of its catalytic activity.
