The stereoselective synthesis of P-chiral phosphines through the additions onto the P=C double bond of prochiral phosphaalkenes

通过加成前手性磷烯的 P=C 双键立体选择性合成 P-手性膦

• 批准号: 17550107
• 负责人: MINAMI Tatsuya
• 金额: $ 2.18万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2005
• 资助国家: 日本
• 起止时间: 2005 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17550107/
• 关键词: Phosphapalladacyclopropanes; Alkoxypalladation; Arylphosphaalkenes; P-C-S pincer ligand; P-chiral phosphines; Thiophosphine; 第三級ホスフィン; ホスファアルケン

(1) Diastereoselective Synthesis of Phosphapalladacyclopropanes by Alkoxypalladation of Arylphosphaalkenes Bearing ortho-Benzylic Heteroatom SubstituentAlkoxypalladation of the kinetically protected arylphosphaalkenes bearing a coordinative heteroatom substituent at the ortho-benzylic positeion gave the phosphapalladacyclopropane complexes stereoselectively. The complexes were found to be stable to silica gel chromatography in the air. The benzylic heteroatom substituent of arylphosphaalkenes acts as the ligand of the resulting palladium (II) complexes. The diastereoselectivity of this reaction is mainly controlled by the heteroatom substituent at the benzylic stereogenic center. We have found a novel approach for the synthesis of enantio-pure P-C-S pincer ligand coordinated palladium complexes.(2) Nucleophilic Addition of Thiolate Anion to Tricarbonylchromium-Coordinated ArylphospaalkenesThe stereoselective additions onto the P=C double bond of prochiral phosphaalkenes are one of the efficient method for the synthesis of P-chiral phosphines. However, the reactivity of sterically protected phosphaalkenes, which are stable in the air, is rather low. Tricarbonylchromium-coordinated arylphosphaalkenes are expected to increase the reactivity toward nucleophiles, because the tricarbonylchromium fragment stabilizes benzylic carbanions due to its strong electron-withdrawing ability. Although (E)-2-phenyl-1-(2,4,6-tri-t-butylphenyl)phosphaethene did not reacted with lithium thiolate in THF, the corresponding chromium complex gave thiophosphine in excellent yield. We have found a new method for the synthesis of bulky P-chiral ligands.

(1)通过带有邻位苄基杂原子取代基的芳基磷烯的烷氧基钯化非对映选择性合成磷环丙烷对在邻位苄位上带有配位杂原子取代基的动力学保护的芳基磷烯进行烷氧基钯化，得到 磷酸环丙烷立体选择性配合物。发现该配合物对于空气中的硅胶色谱是稳定的。芳基磷烯的苄基杂原子取代基充当所得钯(II)络合物的配体。该反应的非对映选择性主要由苯甲基立体中心的杂原子取代基控制。我们发现了一种合成对映纯P-C-S钳配体配位钯配合物的新方法。(2)硫醇阴离子与三羰基铬配位的芳基磷烯的亲核加成前手性磷烯的P=C双键上的立体选择性加成是合成P-C-S钳配体的有效方法之一。 P-手性膦。然而，空间保护的磷烯在空气中稳定，其反应活性相当低。三羰基铬配位的芳基磷烯有望提高对亲核试剂的反应活性，因为三羰基铬片段具有很强的吸电子能力，可以稳定苄基碳负离子。尽管(E)-2-苯基-1-(2,4,6-三叔丁基苯基)磷乙烯不与硫醇锂在THF中反应，但相应的铬络合物以优异的收率得到硫代膦。我们发现了一种合成大体积 P-手性配体的新方法。