Synthesis of new chiral 2,2'-bipyridine ligands and their application in copper-catalyzed asymmetric allylic oxidation and cyclopropanation.
Synthesis of new chiral 2,2'-bipyridine ligands and their application in copper-catalyzed asymmetric allylic oxidation and cyclopropanation.
复制标题
DOI：
10.1021/jo034179i
复制
发表时间：
2003-05
期刊：
影响因子：
--
通讯作者：
A. Malkov;Daniele Pernazza;M. Bell;M. Bella;A. Massa;F. Teplý;P. Meghani;P. Kočovský
中科院分区：
文献类型：
--
作者：
A. Malkov;Daniele Pernazza;M. Bell;M. Bella;A. Massa;F. Teplý;P. Meghani;P. Kočovský
通过吡啶核的从头构建，合成了一系列模块化联吡啶型配体1和3-9。这些配体的手性部分来自类异戊二烯手性库，即分别为β-蒎烯（10 -> 1）、3-<$烯（14 -> 3和5）、2-<$烯（28 -> 4）、α-蒎烯（43 -> 6-8）和脱氢双烯醇酮乙酸酯（48 -> 9）。由这些配体和（TfO）（2）Cu（1 mol %）在苯肼原位还原时得到的铜（I）配合物在环烯烃的烯丙基氧化中表现出良好的对映选择性（高达82% ee）和异常高的反应速率（典型地在室温下30 min）（52 -> 53）。用55 + 56进行铜催化的环丙烷化）。的不对称诱导的水平进行了讨论的配体结构，控制的立体化学环境的配位金属。
A series of modular bipyridine-type ligands 1 and 3-9 has been synthesized via a de novo construction of the pyridine nucleus. The chiral moieties of these ligands originate from the isoprenoid chiral pool, namely, beta-pinene (10 --> 1), 3-carene (14 --> 3 and 5), 2-carene (28 --> 4), alpha-pinene (43 --> 6-8), and dehydropregnenolone acetate (48 --> 9), respectively. Copper(I) complexes, derived from these ligands and (TfO)(2)Cu (1 mol %) upon an in situ reduction with phenylhydrazine, exhibit good enantioselectivity (up to 82% ee) and unusually high reaction rate (typicaly 30 min at room temperature) in allylic oxidation of cyclic olefins (52 --> 53). Copper-catalyzed cyclopropanation proceeded with 55 + 56). The level of the asymmetric induction is discussed in terms of the ligand architecture that controls the stereochemical environment of the coordinated metal.