Intramolecular Non-covalent Interactions in Metal Complexes : Geometrical Controles and Stereoselective Reactions

研究了4- （l-甲基氧基）-1-苯基- 1,3 -丁二酮（H (l-moba)）和4- （l-甲基氧基）-1-对- 1,3 -丁二酮（H (l-moba- me)）六配位配合物对不同金属离子（Co, Cr, Mn， IIIA， IIIB, ithanoid）的立体选择性。特别是用400 MHz H-NMR和CD谱研究了IIIA和IIIB离子的配合物。所有配合物都表现出立体选择性，主要是由于左旋三叶螺旋桨的非共价相互作用，包括三个配体间的l-薄荷基/芳基接触。当中心金属离子显著增大时，配体间的接触效率显著提高。这种立体控制的类镧配合物Ln (l-moba-Me)_3被用作路易斯酸催化剂，用于酮类的对映选择性还原。苯乙酮转化为(S) -醇（e % 84），而丁烷-2- 1和辛烷-2- 1转化为(R) -醇。采用单晶x射线、CD光谱和分子力学计算研究了N- (l-menthyl)水杨醛二胺（H (salt - rmb)）和N- (R) -甲基苄基水杨醛二胺（H (sal-Rmb)）的四面体或拟四面体Co （II）、Cu- (II)和Zn （II）配合物的电活性。四面体[M（盐）_2]（M=Co, Cu, Zn）的首选构型为DELTA，四面体[M（盐）_2]（M=Co, Zn）的首选构型为OMEGA，伪四面体[Cu（盐）_2]的首选构型为DELTA。[M (sal-Rmb)_2]的x射线结构分析清楚地证明了手性n取代基与邻环之间存在非共价相互作用。偶亚甲基pi-pi^*跃迁引起的棉花效应与金属中心的绝对构型密切相关。用电子吸收和CD光谱研究了N- {(R) - α -甲基苄基}乙二胺（R-mben）、N- {(S) - α -甲基苄基}乙二胺（S-mben）和N- （l-甲基）-乙二胺（mten）的平面金属（II）配合物（M=Cu, Pb, Pt）的立体选择性，并根据区域规则（十六进制规则）解释了它们的立体选择性。对于mten和B-mben配合物，乙烯链的优先构象为δ，而对于S-mben配合物，则为λ。少

Stereoselectivities of six-coordinate complexes of 4- (l-menthyloxy) -1-phenyl-1, 3-butanedione (H (l-moba) ) and 4- (l-menthyloxy) -1-p-tolly-1, 3-butanedione (H (l-moba-Me) ) have been examined for various metal ions (Co, Cr, Mn, IIIA, IIIB, Ianthanoid). In particular the complexes of IIIA and IIIB ions were studied by means of 400 MHz H-NMR and CD spectroscopies. All the complexes showed a stereoselectivity to afford the fac-OMEGA from predominantly because of the operation of a non-covalent interaction in the from of a left-handed three-bladed propeller, comprising three interligand l-menthyl/aryl contact. The interligand contact became efficient when the central metal ion was significantly large (r>l.OA^^ﾟ).Such sterically controlled lanthanoid complexes Ln (l-moba-Me)_3 were used as Lewis acid catalysts for enantioselective reductions of ketones. Acetophenone was converted into (S) -alcohol (e e % 84) whereas butane-2-one and octane-2-one were converted into (R) -alchols.Stereose … More lectivities of tetrahedral or pseudo-tetrahedral Co (II), Cu- (II), and Zn (II) complexes of N- (l-menthyl) salicylaldimine (H (sal-ment) ) and N- (R) -alpha-methylbenzylsalicylaldimine (H (sal-Rmb) ) have been studied by single-crystal X-ray method, CD spectroscopy, and molecular mechnics Calculations. The preferred configuration was DELTA for tetrahedral [M (sal-ment)_2] (M=Co, Cu, Zn), OMEGA for tetrahedral [M (sal-Rmb)_2] (M=Co, Zn), and DELTA for pseudo-tetrahedral [Cu (sal-Rmb)_2]. The X-ray structural analyses for [M (sal-Rmb)_2] clearly demonstrated the operation of non-covalent interactions between the chiral N-substituent and the adjacent ring. The Cotton effect induced at the azomethine pi-pi^* transition was well correlated with the absolute configration about the metal center.Stereoselectivities of planar metal (II) complexes (M=Cu, Pb, Pt)) of N-substituted ethylenediamines, N- { (R) -alpha-methylbenzyl} ethylenediamine (R-mben), N- { (S) -alpha-methylbenzyl} ethylenediamine (S-mben), and N- (l-menthyl) -ethylenediamine (mten), have been examined by electronic absorption and CD spectroscopies and interpreted based on a regional rule (hexadecadalrule). The preferred conformation with respect to the ethylene chain were delta for the mten and B-mben complexes and lambda for the S-mben complexes. Less