名称:
Reactions of nitrones with transition metal nitrile complexes: cycloaddition, ligand substitution, or hydrolysis
摘要:
The reaction of nitrones with transition metal nitrile complexes of the type [MCl2(PhCN)(2)] and [MCl4(MeCN)(2)] leads to different products, depending on the metal. Reaction of [PdCl2(PhCN)(2)] with RCH=N(Me)O (R=Ph, p-C6H4Me) afford Delta(4)-1,2,4-oxadiazoline complexes [PdCl2{N=C(Ph)O-N(Mc)CH(R)}(2)] as products of [2+3] cycloaddition of the nitrone across the Cequivalent toN bond of the nitrile. The oxophilic transition metal compounds [TiCl4(MeCN)(2)] and [ZrCl4(MeCN)(2)] undergo rapid ligand exchange to form nitrone complexes from which the nitrone can be released without decomposition. The closely related compounds [MoCl4(MeCN)(2)] and [WCl4(MeCN)(2)] mediate the hydrolysis of nitrones to the corresponding aldehydes. (C) 2003 Elsevier B.V. All rights reserved.