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

摘要

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 alpha-carbon. When using the 2,6-diphenylpyrylium salt, a gamma-addition of the amino group occurred, leading after an hydrogen migration and a ring opening step - to the new organometallic unsaturated ammoketone 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. (c) 2007 Elsevier B.V. All rights reserved.