Selective hydrogenation of naphthalene to tetralin was conducted by using Ni–Al intermetallic compounds (IMCs) prepared by a chemical synthetic route. Ni–Al IMC catalysts achieved a lasting high conversion with 100 % selectivity up to 125 h. During the synthesis process, the Ni–Al IMCs underwent the following phase transformation as a function of the content of the Al source (LiAlH4): Ni(cubic)→Ni3Al(tetragonal)→NiAl(cubic)→Ni2Al3(hexagonal). In the selective hydrogenation of naphthalene, the catalytic activity of NiAl was much higher than that of metallic Ni and other Ni–Al IMCs (Ni3Al and Ni2Al3). The results can be understood by a combination of site isolation and alteration of the electronic structure by chemical bonding. Ni atoms are scattered and spatially isolated by Al atoms, which in turn resists carbon deposition. The findings provide a useful approach to tailor the catalytic properties of transition metals by formation of IMCs, which could be applicable in heterogeneous catalysis.

An efficient approach for the synthesis of benzo-fused pyridoindolone derivatives via a one-pot copper catalyzed tandem reaction of 2-iodobenzamides with 2-iodobenzylcyanides has been developed. Using this protocol, benzo-fused pyridoindolone derivatives are obtained in high yields in a relatively short period of time under mild reaction conditions. To the best of our knowledge, this is the first approach where one can synthesize free indole N-H benzo-fused pyridoindolones. Also, both indole and pyridone cores are constructed during the course of the reaction. The methodology shows good functional group tolerance and allows synthesis of thiophene-fused pyridoindolones and fused indolobenzonaphthyridone derivatives.

A one‐pot reaction has been devloped for the preparation of 1,2,3‐fused indole polyheterocycles by starting from 2‐iodobenzamide and 2‐iodobenzyl cyanide in the presence of a copper catalyst. The cascade process involves the efficient formation of one C–C and three C–N bonds. A broad substrate scope, good yields, and short reactions times are key features of this strategy.

No abstract