A Tetrakis(tetrazolyl) Analogue of EDTA

• Published in: European Journal of Organic Chemistry 2009-04, Vol.2009 (10), p.1495-1498
• Main Authors: Touti, Faycal, Maurin, Philippe, Hasserodt, Jens
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Chemistry; Coordination compounds; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Inorganic chemistry and origins of life; Isosteres; N ligands; Nitrogen heterocycles; Organic chemistry; Preparations and properties; Protecting groups
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.200900016

The tetrazole moiety is usually established in situ with the corresponding inconveniences, such as reactant incompatibility, yield. In most of these cases, the tetrazole is formed in its nonprotected form. Subsequent protection is unattractive because of the promiscuous formation of two regioisomers. No particular protecting group has seen widespread use. The growing field of site‐selective oxidation of unactivated hydrocarbons makes use of metal complexes based on multidentate ligands displaying nitrogen coordination sites. We have characterized an easily accessible, benzyl‐protected synthon that allows the convergent introduction of the tetrazolylmethyl moiety and its smooth deprotection by catalytic hydrogenation. With the straightforward synthesis of the new hexadentate ligand EDTT, we have demonstrated the utility of this synthon for the fields of coordination, medicinal, and organocatalytic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) A synthon for the convergent introduction of a protected tetrazole moiety intonucleophile‐bearing molecules is presented. Benzyl deprotection is accomplished under neutral conditions. The usual in situ establishment of the tetrazole moiety is thusavoided, as is the lack of regioselective control during subsequent protection. The exemplary synthesis of a new isoelectronic analogue of EDTA is presented.