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首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Synthesis of C_2-symmetric aza- and azaoxa-macrocyclic ligands derived form (1R,2R)-1,2-diaminocyclohexane and their applications in catalysis
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Synthesis of C_2-symmetric aza- and azaoxa-macrocyclic ligands derived form (1R,2R)-1,2-diaminocyclohexane and their applications in catalysis

机译：（1R，2R）-1,2-二氨基环己烷衍生的C_2对称氮杂-和氮杂-大环配体的合成及其在催化中的应用

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Investigations have been undertaken into the synthesis of chiral derivatives of 1,4,7-triazacyclononane and 1,7-diaza-4-oxacyclononane that incorporate the C_2-symmetrc (R,R)-1,2-diaminocyclohexane backbone.The target ligands 17a and 17b have been prepared as their hydrochloride salts,the latter of which has been characterized by single crystal X-ray diffraction revealign an extensively hydrogen bonded polymeric network in the solid state.These investigations have shown that the formation of the fused bicyclic system in these ligands via standard Richman-Atkins macro-cyclisation condition is extremely difficult,paticular for the intermediate 16a,when three tosyl amide nitrogen atoms must be accommodated in the macrocyclic ring.In addition to these target lignads the unexpected piperazine 15 as well as the novel binucleating ligand 19 have also been prepared.Preliminary investigation into the coordination chemistry of 17b resulted in the fromation of the copper(II) complex[Cu(17b)Cl_2] in which the copper centre exists in the copper cnetre exists in the expected square-pyramidal geometry with the two chloride ions and the nitrogen donors occupying the equatorial positions and with the oxygen donor apically situated.The complex has been screened for activity and found to be a potent catalyst for two hetero-Diels-Alder reactions.The first aza-Diels-Alder reaction of imine 20 with Danishefsky's diene 21 proceeds to yield the cycloadduct 22 in 94% yield.The second nitroso-Diels-Alder reaction relies on teh in situ oxidationof hydroxylamine 23to dienophile 24,catalysed by te complex in the presence of tert-butyl hydroperoxide,which is then trapped as cycloadduct 25 by cyclohexadiene in 69% yield.
机译：已经研究了结合有C_2-对称（R，R）-1,2-二氨基环己烷骨架的1,4,7-三氮杂环壬烷和1,7-二氮杂-4-氧杂环壬烷的手性衍生物的合成。已经制备了17a和17b的盐酸盐，其盐的特征在于单晶X射线衍射揭示了固态的氢键广泛的聚合物网络。这些研究表明，稠合的双环体系的形成。通过标准Richman-Atkins大环化条件，这些配体非常困难，特别是对于中间体16a，当大环中必须容纳三个甲苯磺酰胺氮原子时。除这些目标外，未曾预料到的哌嗪15和新型还制备了双核配体19。对17b配位化学的初步研究导致了铜（II）配合物[Cu（17b）Cl_2]的形成其中铜中心存在于铜中心中，以预期的方金字塔形几何结构存在，其中两个氯离子和氮供体占据赤道位置，并且氧供体顶端位于位置。亚胺20和Danishefsky的二烯21的第一个氮杂-Diels-Alder反应进行，以94％的收率得到环加合物22.第二个亚硝基-Diels-Alder反应依赖于在叔丁基氢过氧化物的存在下，由络合物催化将羟胺23原位氧化为亲二烯体24，然后环己二烯将其作为环加合物25捕获，收率为69％。

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