Lithium-Titanium Exchange of Tertiary α-Sulfonyl Carbanions: Synthesis, Structure, Dynamics and Reactivity of Bis(1-sulfonylalkyl)titaniums
作者:Thomas Heß、Gerhard Raabe、Hans-Joachim Gais
DOI:10.1002/ejoc.201402896
日期:2014.11
stable at room temperature towards β-H elimination. They selectively add to benzaldehyde in the presence of acetophenone but do not react with methyl iodide. The reaction of tertiary acyclic α-sulfonyl carbanions with ClTi(OiPr)3 in tetrahydrofuran (THF) gives different titanium derivatives with unspecified structures, which not only selectively react with benzaldehyde in the presence of acetophenone
叔α-磺酰基碳负离子与ClTi(OiPr)3 和Cl2Ti(OiPr)2 在乙醚中的锂-钛交换得到双(1-磺酰基烷基)钛,而不是相应的(1-磺酰基烷基)钛。二(异丙氧基)双[1-(苯磺酰基)环丁基]钛和二(异丙氧基)双[1-(苯磺酰基)异丙基]钛的X射线晶体结构分析显示不对称扭曲八面体配合物,具有六配位Ti原子,两个C- Ti 键、四个 Ti-O 键和两个四元 Ti-O-S-Cα 环。根据 1 H NMR 光谱,双(1-磺酰基环烷基)钛在室温下是非流动的。这表明手性双(1-磺酰基烷基)钛应该是构型稳定的。双(1-磺酰基烷基)钛在室温下对 β-H 消除是稳定的。它们在苯乙酮的存在下选择性地添加到苯甲醛中,但不与甲基碘反应。叔无环 α-磺酰基碳负离子在四氢呋喃 (THF) 中与 ClTi(OiPr)3 反应生成不同结构的钛衍生物,它们不仅在苯乙酮存在下选择性地与苯甲醛反应,而且还被甲基碘烷基化。