Synthesis, Characterization, and Diastereoselectivity of Chloride Substitution Reactions of Cycloruthenated (R)_C-(+)-<i>N</i>,<i>N</i>-Dimethyl-α-(2-naphthyl) Ethylamine

The transmetalation reaction of enantiomerically pure 1, with [(η6-C6H6)RuCl2]2 in CH3CN at ambient temperature forms a mixture of two diastereomeric ruthenacycles (SRu, RC), 2a, (96%) and (RRu, RC), 2a‘, (4%) of the type in good chemical and optical yields. The diastereoselectivity of chloride substitution in 2a,a‘ by bromide, iodide, azide, cyanate, thiocyanate, nitrite, allylisonitrile, and selected nitrogen and phosphorus donor ligands has been determined by an appropriate combination of 1H, 13C{1H}, and 31P{1H} NMR spectroscopy, UV−visible spectroscopy, circular dichroism, and single-crystal X-ray crystallography. The diastereoselectivity generally increases with increasing steric bulk of the incoming ligand and proceeds with predominant retention of configuration at ruthenium. The ambidentate ligands, cyanate, thiocyanate, and nitrite all bond to ruthenium exclusively through their nitrogen donor atoms.对映纯的化合物1与(η⁶-苯)二氯化钌二聚体([(η⁶-C₆H₆)RuCl₂]₂)在乙腈(CH₃CN)中于室温下发生转金属化反应，生成两种非对映异构的钌杂环产物：构型为(SRu, RC)的2a（产率96%）与构型为(RRu, RC)的2a'（产率4%），该反应具备良好的化学产率与光学产率。通过1H核磁共振波谱(¹H NMR)、13C{¹H}核磁共振波谱(¹³C{¹H} NMR)、31P{¹H}核磁共振波谱(³¹P{¹H} NMR)、紫外-可见光谱(UV−visible spectroscopy)、圆二色谱(circular dichroism)以及单晶X射线衍射(single-crystal X-ray crystallography)的联用分析，我们确定了溴离子、碘离子、叠氮根、氰酸根、硫氰酸根、亚硝酸根、烯丙基异腈以及部分精选氮、磷给体配体对2a与2a'中氯原子的取代反应的非对映选择性。该取代反应的非对映选择性通常随进攻配体的空间位阻增大而提升，且反应过程中钌中心的构型主要发生保留。两可配体(ambidentate ligands)氰酸根、硫氰酸根与亚硝酸根均仅通过其氮给体原子与钌成键。