The Heck reaction, one of the most utilized cross-coupling reactions, is the palladium-catalyzed arylation of an olefin with an aryl halide under basic conditions. It has drawn much attention due to high efficiency and simplicity. Heck methodology is attractive from a synthetic point of view because of its high chemoselectivity and mild reaction conditions along with low toxicity and cost of the reagent if, specifically, the catalyst is recycled. Fig (1): Heck reaction of an olefin with an aryl halide under basic conditions The Heck reaction is described as a vinylation or arylation of olefins where a large variety of olefins can be used, like derivatives of acrylates, styrenes or intramolecular double bonds [2]. The aryl halide variants developed in addition to typical aryl bromides and iodides are aromatic triflates, aroyl chlorides, aryl sulfonyl chlorides, aromatic diazonium salts, aroyl anhydrides, aryl chlorides and arylsilanols [3] The Fibroin/ Pd nanoparticles showed high catalytic activity in the heck coupling reaction. Attractive features of this protocol are high yields, simple procedure with an easy work-up, and recyclability and reusability of the catalyst. References [1]: Li, H.; Johansson, S.; Carin, C.C.; Colacot, T.J. Development of preformed Pd Catalysts for crosscoupling reactions, beyond the 2010 Nobel Prize. ACS Catal. 2012, 2, 1147 1164 [2]: Heck, R.F.; Nolley, J.P. Palladium-catalyzed vinylic hydrogen substitution reactions with aryl, benzyl, and styryl halides. J. Org. Chem. 1972, 37, 2320 2322. [3]: Beletskaya, I.P.; Cheprakov, A.V. The Heck reaction as a sharpening stone of palladium catalysis. Chem. Rev. 2000, 100, 3009 3066.

Keywords