Beilstein J. Org. Chem.2021,17, 1001–1040, doi:10.3762/bjoc.17.82
: amidine; biguanide; guanidine chemistry; metformin derivatives; polynitrogenligands; synthetic methodology; Introduction
Biguanide – or amidinoguanidine – is a chemical compound derived from guanidine in which two guanidine molecules are linked through a common nitrogen atom. Since its first synthesis
Beilstein J. Org. Chem.2016,12, 2471–2477, doi:10.3762/bjoc.12.241
alkylations of amines and ammonia with azoalkenes (generated from α-halohydrazones) were demonstrated as an efficient approach to poly(hydrazonomethyl)amines – a novel class of polynitrogenligands. An intramolecular cyclotrimerization of C=N bonds in tris(hydrazonomethyl)amine to the respective 1,4,6,10
1a was used to ensure complete alkylation). Macrocyclic polynitrogenligands with several hydrazone arms may be of interest for the design of sensors [52] and contrast agents [53].
Unfortunately, alkylation of ethylenediamine with 4 equivalents of 1a led to an indecipherable mixture of products. In