Larock Indole Synthesis Using Immobilized Palladium Complexes

2 Larock Indole Synthesis Using Immobilized Palladium Complexes 

Heterogeneous palladium catalysts have been prepared by covalent immobilization of palladium (11) complexes onto SBA-15 sdica. The heteroannu-lation of 2-iodoaniline with triethyl(phenylethynyl)silane using these preformed palladium complexes gives excellent yields in Larock synthesis of indoles. These palladium catalysts have been demonstrated to be recyclable through multiple recycling experiments (2010MI179). 

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N. Batah, A. Bendjeriou, L. Djakovitcha, V. Dufaud, Larock indole synthesis using palladium complexes immobilized onto mesoporous silica, Appl. Catal. A Gen. 388 (2010) 179-187. 

Ring Closure Reactions Palladium(II) complexes (PdCl2L2, L=P, CN), covalently immobilized onto SBA-15 silica by a postsynthetic method, were used as catalysts in the Larock synthesis of indoles [86]. The reaction consisted of the heteroannulation of 2-iodoaniline and 2-bromoaniline with triethyl(phenylethynyl)silane showing high activities and selectivities to 3-phenyl-lH-indole 26 (Scheme 17). 

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