Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon, Portugal.
Chemistry. 2012 Jan 16;18(3):899-914. doi: 10.1002/chem.201101688. Epub 2011 Dec 14.
Template combination of copper acetate (Cu(AcO)(2)⋅H(2)O) with sodium dicyanamide (NaN(C≡N)(2), 2 equiv) or cyanoguanidine (N≡CNHC(=NH)NH(2), 2 equiv) and an alcohol ROH (used also as solvent) leads to the neutral copper(II)-(2,4-alkoxy-1,3,5-triazapentadienato) complexes [Cu{NH=C(OR)NC(OR)=NH}(2)] (R = Me (1), Et (2), nPr (3), iPr (4), CH(2)CH(2)OCH(3) (5)) or cationic copper(II)-(2-alkoxy-4-amino-1,3,5-triazapentadiene) complexes Cu{NH=C(OR)NHC(NH(2))=NH}(2)(2) (R = Me (6), Et (7), nPr (8), nBu (9), CH(2)CH(2)OCH(3) (10)), respectively. Several intermediates of this reaction were isolated and a pathway was proposed. The deprotonation of 6-10 with NaOH allows their transformation to the corresponding neutral triazapentadienates [Cu{NH=C(OR)NC(NH(2))=NH}(2)] 11-15. Reaction of 11, 12 or 15 with acetyl acetone (MeC(=O)CH(2)C(=O)Me) leads to liberation of the corresponding pyrimidines NC(Me)CHC(Me)NCNHC(=NH)OR, whereas the same treatment of the cationic complexes 6, 7 or 10 allows the corresponding metal-free triazapentadiene salts {NH(2)C(OR)=NC(NH(2))=NH(2)}(OAc) to be isolated. The alkoxy-1,3,5-triazapentadiene/ato copper(II) complexes have been applied as efficient catalysts for the TEMPO radical-mediated mild aerobic oxidation of alcohols to the corresponding aldehydes (molar yields of aldehydes of up to 100 % with >99 % selectivity) and for the solvent-free microwave-assisted synthesis of ketones from secondary alcohols with tert-butylhydroperoxide as oxidant (yields of up to 97 %, turnover numbers of up to 485 and turnover frequencies of up to 1170 h(-1)).
醋酸铜（Cu(AcO)(2)⋅H(2)O）与草酰胺（NaN(C≡N)(2)，2 当量）或氰胺（N≡CNHC(=NH)NH(2)，2 当量）和醇 ROH（也用作溶剂）的模板组合，导致中性铜（II）-(2,4-烷氧基-1,3,5-三嗪戊二烯基)配合物[Cu{NH=C(OR)NC(OR)=NH}(2)]（R = Me（1）、Et（2）、nPr（3）、iPr（4）、CH(2)CH(2)OCH(3)（5））或阳离子铜（II）-(2-烷氧基-4-氨基-1,3,5-三嗪戊二烯基)配合物Cu{NH=C(OR)NHC(NH(2))=NH}(2)(2)（R = Me（6）、Et（7）、nPr（8）、nBu（9）、CH(2)CH(2)OCH(3)（10）），分别。该反应的几个中间体被分离出来，并提出了一种途径。用 NaOH 对 6-10 进行脱质子化处理，允许它们转化为相应的中性三嗪戊二烯[Cu{NH=C(OR)NC(NH(2))=NH}(2)]11-15。将 11、12 或 15 与乙酰丙酮（MeC(=O)CH(2)C(=O)Me）反应导致相应的嘧啶 NC(Me)CHC(Me)NCNHC(=NH)OR 的释放，而对阳离子配合物 6、7 或 10 进行相同的处理允许分离相应的无金属三嗪戊二烯盐{NH(2)C(OR)=NC(NH(2))=NH(2)}(OAc)。烷氧基-1,3,5-三嗪戊二烯/ato 铜（II）配合物已被用作高效催化剂，用于 TEMPO 自由基介导的醇温和有氧氧化为相应的醛（醛的摩尔产率高达 100%，选择性大于 99%），以及用于叔丁基过氧化氢作为氧化剂的无溶剂微波辅助合成酮（产率高达 97%，转化率高达 485，转化频率高达 1170 h(-1)）。
