Additions and corrections

Novel bisimidazolium pincers as low loading ligands for in situ palladium-catalyzed Suzuki–Miyaura reaction in the ambient atmosphere

Chao Gao, Hongjun Zhou, Siping Wei, Yinsong Zhao, Jingsong Youa and Ge Gao

Chem. Commun., 2013, 49, 1127–1129 (DOI: 10.1039/C2CC36375E). Amendment published 23rd August 2013.

We recently reported a facile synthesis of triazinonide-bridged bisimidazolium pincers (Scheme 1). The coupling of trichlorotriazine (TCT) with 2.2 equivalents of an N-substituted imidazole in pretreated CH3CN to afford triazinonide-bridged bisimidazolium pincer B through hydrolysis of the unstable intermediate A. Unlike aryl pincers (R = aryls), a low temperature of 0 ˚C was necessary for alkyl pincers (R = alkyls) because further hydrolysis occurred very easily to afford compound C at higher temperature. The X-ray analyses confirmed the triazinonide-bridged structure B and further hydrolyzed structure C.



In the process of our work, Alexander Poethig and Thomas Strassner reported a similar but different structure: triazinol-bridged bisimidazolium pincers F which correspond to HCl adducts of the triazinonide-bridged salts reported by us and were obtained by a temperature-programmed reaction (addition at 0 ˚C, 30 min at rt, 30 min at 60 ˚C and 4.5 h at 110 ˚C) starting from TCT with a large excess of N-substituted imidazoles in a CH3CN/H2O solvent mixture (Scheme 2). The triazinol bridge was transformed into a triazinonide bridge after these pincers formed complexes with silver. See: ref 16a, Organometallics 2011, 30, 6674–6684.



Based on the above comparison, the two similar but different reaction conditions led to two similar but different pincer structures. Nevertheless, the use of the word “novel” is inappropriate, and the above mentioned article should have been acknowledged and discussed in detail in the communication.

The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.

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