Radical vicinal carbohalofunctionalization of C-C multiple bonds via atom transfer processes constitutes an efficient method for the construction of halgenated building blocks with complete atom economy. This review summerizes the...

Transition-metal-catalyzed 1,2-carbohalofunctionalization reactions of CÀ C multiple bonds have emerged rapidly over the past decade as a powerful tool for generating a new carbon-carbon and carbon-halogen bond via transposition of an existing carbon-halogen σ bond. Exploring this highly efficient mode of carbon-carbon multiple bond difunctionalization, various research groups have established novel strategies for the synthesis of organohalides by utilizing wide variety of transition metal catalysts under mild reaction conditions, avoiding stoichiometric waste of by-products, and with improved levels of chemo-, regio-, and stereoselectivities. Most of the 1,2-carbohalo-functionalization reactions involve either the carbon-halogen reductive elimination mechanism or the atom transfer radical addition (ATRA) mechanism. This review summarizes the recent progress in the area of transitionmetal-catalyzed intra-and intermolecular 1,2-carbo-halo-functionalization reactions of carbon-carbon multiple bonds and explicates the underlying potentiality and challenges within the field.

Herein, we disclose the first report on iodo-cycloisomerization of 1-(indol-3-yl)-1-arylbut-3-yn-2-ols to form 3-iodocarbazoles. The synthesis proceeds through a cascade 5-endo-spirocyclization, followed by selective 1,2-alkyl migration. This method governs the green synthesis principles such as open-flask reaction, AcOEt as the solvent, rt reaction with short time, use of iodine, and broad substrate scope with atom and step economy.

An unprecedented Au­(I)-catalyzed domino intramolecular carbonyl-alkyne cyclization/indole addition strategy has been disclosed here. This generalized strategy enables the synthesis of 3­(2H)-furanone-incorporated unsymmetrical bis­(indolyl)­methanes with generation of a stereocenter at the furanone junction from easily accessible indole-tethered ynediones. In addition, this present protocol could also be extended for the synthesis of a number of indolyl-(hetero)­arylmethanes by employing a variety of (hetero)­arenes as a nucleophile coupling partner.