Correction to: Res Chem Intermed (2017) 43:3291–3305 https://doi.org/10.1007/s11164-016-2826-y

Since it has been cleared that a fake compound has been sold to us as cyanoform, and since we have unintentionally used this fake compound for preparation of the catalyst, therefore, we prepare an Erratum on our published paper. The reported errors are including the procedure for the synthesis of catalyst and its characterization part. These errors were corrected by applying a known alternative method for the synthesis of catalyst [1]. Also, we corrected our reported data in the case of the optimization of reaction conditions and the scope of the reported protocol for the synthesis of target molecules. According to these amendments, the authors acknowledge that the mentioned paper has been corrected.

In this, according to the Banert's suggestion for providing a fundamental correction and based on their procedure [1], we prepared 1H-imidazol-3-ium tricyanomethanide by applying potassium tricyanomethanide [2,3,4]. The new optimized reaction conditions is where the model reaction for the synthesis of 1j was performed in the presence of 2 mol% of 1H-imidazol-3-ium tricyanomethanide at 70 °C under solvent free conditions. Therefore, Table 2 in original paper was corrected with new results as follows (Table 1). Reusability test of the catalyst was not successful.

Table 1 Synthesis of pyrano[4,3-b]pyrans in the presence of 1H-imidazol-3-ium tricyanomethanide
Full size table