Selective reactivity of diamino Fischer-type carbene complexes towards 2,6-disubstituted and 2,4,6-trisubstituted pyrylium salts and 2,4,6-trichloro-1,3,5-triazine

• Published in: Journal of organometallic chemistry Vol. 692; no. 17; pp. 3599 - 3605
• Main Authors: Le Poul, P., Caro, B., Robin-Le Guen, F.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-08-2007; Elsevier
• Subjects: 1,3-Hydride transfer; Aminolysis; Chemical Sciences; Coordination chemistry; Pyridinium Fischer-type carbene complex; Pyrylium salt; Pyrylium salt; Aminolysis; 1,3-Hydride transfer; Pyridinium Fischer-type carbene complex
• ISSN: 0022-328X; 1872-8561; 0022-328X
• DOI: 10.1016/j.jorganchem.2007.05.034

The reaction of alkoxy Fischer-type carbene complexes with diamines gave amino carbenes with pendent NH
2. The free amino group of these complexes which could act as markers for biomolecules reacted with pyrylium salts to give pyridinium salts or a new 1,5-organometallic aminoketone. In addition, reaction with 2,4,6-trichloro-1,3,5-triazine gave a monosubstituted product.
The synthesis of new amino Fischer-type carbene complexes
2a–
d with amino-containing side chain is presented. The reaction of these complexes with 2,4,6-triarylpyrylium salts gave the corresponding pyridinium salt
4a,
4c–
e as expected from the initial attack of the free amino group onto the pyrylium α-carbon. When using the 2,6-diphenylpyrylium salt, a γ-addition of the amino group occurred, leading – after an hydrogen migration and a ring opening step – to the new organometallic unsaturated aminoketone
5. Finally, the reactivity of the diaminocarbene
2b with 2,4,6-trichloro-1,3,5-triazine has been investigated. The new triazine
6 bearing a ferrocenylaminocarbene group was isolated.