Additions and corrections
The use of hydrazones for efficient Mannich type coupling with aldehydes and secondary amines
Valérie Atlan, Hugues Bienaymé, Laurent El Kaim and Adinath Majee
Chem. Commun., 2000, 1585 (DOI: 10.1039/b002750m). Amendment published 6th March 2003.
The authors would like to point out the following errors in the structural assignments of compounds 4f and 4m. Instead of the proposed Mannich adducts, the additions of α,β-unsaturated aldehydes 2e and 2g proceed to give pyridazines 1 and 2 in a Michael type addition reaction followed by cyclisation. The structure of 1 was proven by two different syntheses of 3 (elimination of N-benzylpiperazine from 1 and [4+2] cycloaddition with enol ether). For related Michael type additions of monoalkylhydrazone see: H. Buff, U. Kuckländer, Tetrahedron, 2000, 56, 5137–5145; V. M. Lyubchanskaya, L. M. Alekseeva, V. G. Granik, Tetrahedron, 1997, 53, 15005–15010; (similar additions with dialkylhydrazones: D. Enders, E. Diez, R. Fernandez, E. Martin-Zamora, J. M. Munoz, R. R. Pappalardo, J. M. Lassaletta, J. Org. Chem. 1999, 64, 6329–6336 and references cited herein).
The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.