108451-18-9Relevant academic research and scientific papers
Organic Syntheses via Transition Metal Complexes, 25. - Cyanoallylation of Carbene Ligands with Allyl Isocyanides via Metal-Induced N/C-Allylic Rearrangement of Intermediate 3-Aza-1,2,5-hexatriene Complexes
Aumann, Rudolf,Kuckert, Eberhard,Heinen, Heinrich
, p. 1293 - 1296 (2007/10/02)
Allyl isocyanides 2 react with (CO)5M=C(OEt)C6H5 (1, M = Cr, W) to give N-allylketenimine/(3-aza-1,2,5-hexatriene) complexes 3 in high yields.In absence of suitable reactants compounds 3 isomerise spontaneously and smoothly already at 0 deg C via a metal-induced N/C-migration of the allyl group to give 4-pentenenitrile complexes 5, from which the ligand can be disengaged by substitution with pyridine.The regiochemistry of the rearrangement corresponds to the type as has been proven by a labeling experiment with α,α-dideuterioallyl isocyanide.In the presence of an alcohol, the reaction of 1 with 2 leads to the formation of competition products resulting from an N/C-rearrangement or the addition of the alcohol to 3, respectively.The competition ratio strongly depends on the type of metal used.The tungsten complex 3b, e.g., at 0 deg C adds one equivalent of an alcohol to give up to 97percent yields of (allylamino)carbene complexes 8b-c, while the corresponding chromium complex 3a rearranges smoothly under these conditions to give 5a only.The addition of alcohols to 3b is reversible: on thermolysis of 8c at 70 deg C the products of thermal isomerisation of 3b together with a chelate complex 9 are obtained.
