Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
J Am Chem Soc. 2010 Nov 17;132(45):15860-3. doi: 10.1021/ja105695s. Epub 2010 Oct 26.
A series of Cu(I)-amido complexes both lacking ancillary ligands and containing 1,10-phenanthroline (phen) as ancillary ligand have been prepared. These complexes react with iodoarenes to form arylamine products, and this reactivity is consistent with the intermediacy of such complexes in catalytic Ullmann amination reactions. The stoichiometric reactions of the Cu(I)-amido complexes with iodoarenes are autocatalytic, with the free CuI generated during the reaction serving as the catalyst. Such autocatalytic behavior was not observed for reactions of iodoarenes with copper(I) amidates, imidates, or phenoxides. The selectivity of these complexes for two sterically distinct aryl halides under various conditions imply that the autocatalytic reaction proceeds by forming highly reactive CuNPh(2) lacking phen. Reactions with radical probes imply that the reactions of phen-ligated Cu(I)-amido complexes with iodoarenes occur without the intermediacy of aryl radicals. Density functional theory calculations on the oxidative addition of iodoarenes to Cu(I) species are consistent with faster reactions of iodoarenes with CuNPh(2) species lacking phen in DMSO than reactions of iodoarenes with LCuNPh(2) in which L = phen. The free-energy barrier computed for the reaction of PhI with (DMSO)CuNPh(2) was 21.8 kcal/mol, while that for the reaction of PhI with (phen)CuNPh(2) was 33.4 kcal/mol.
已经制备了一系列缺乏辅助配体和含有 1,10-菲咯啉（phen）作为辅助配体的 Cu(I)-酰胺配合物。这些配合物与碘芳烃反应生成芳胺产物，这种反应性与这些配合物在催化乌尔曼胺化反应中的中间体一致。Cu(I)-酰胺配合物与碘芳烃的计量反应是自催化的，反应中生成的游离 CuI 充当催化剂。碘芳烃与铜（I）酰胺、异氰酸酯或苯氧基的反应没有观察到这种自催化行为。这些配合物在各种条件下对两种空间位阻明显不同的芳基卤化物的选择性表明，自催化反应是通过形成缺乏 phen 的高反应性CuNPh(2)进行的。与自由基探针的反应表明，与碘芳烃的反应发生在 phen 配体的 Cu(I)-酰胺配合物中，而不是在没有芳基自由基的情况下。对碘芳烃与 Cu(I)物种的氧化加成的密度泛函理论计算表明，在 DMSO 中与缺乏 phen 的 CuNPh(2)物种的反应比与 LCuNPh(2)的反应（其中 L = phen）更快。计算得到 PhI 与（DMSO）CuNPh(2)反应的自由能垒为 21.8 kcal/mol，而 PhI 与（phen）CuNPh(2)反应的自由能垒为 33.4 kcal/mol。
