开发一种通用、高效、对映选择性的催化方法来合成手性醇仍然是一个艰巨的挑战。我们在本文中报道了N-甲基亚氨基二乙酰 (MIDA) 酰基硼酸酯的不对称转移氢化 (ATH) 作为一般的不依赖于底物的进入对映体富集仲醇的方法。具有(杂)芳基、烷基、炔基、烯基和羰基取代基的酰基-MIDA-硼酸酯的 ATH 可产生多种对映体富集的 α-硼醇。后者用于一系列基于硼部分的立体有择转化,能够合成具有两个密切相关的 α-取代基的甲醇,而使用直接不对称氢化方法无法获得高对映选择性,例如 ( R )-氯哌斯汀中间的。计算研究表明,与传统使用的芳基和炔基相比,BMIDA 基团是 Noyori-Ikariya ATH 中的一种优先对映选择性导向基团,因为催化剂的 η 6 -芳烃-CH 和BMIDA 中的 σ 键合氧原子。这项工作扩展了传统 ATH 的领域,并展示了其在解决对称合成挑战方面的巨大潜力。
Acylboronates in Polarity-Reversed Generation of Acyl Palladium(II) Intermediates
作者:Alina Trofimova、Aleksandra Holownia、Chieh-Hung Tien、Martynas J. Širvinskas、Andrei K. Yudin
DOI:10.1021/acs.orglett.1c00742
日期:2021.5.7
process between aryl (pseudo)halides and boron-based acyl anion equivalents. This mode of acylboronate reactivity represents polarity reversal, which is supported by the observation of tetracoordinated boronate and acyl palladium(II) species by 11B, 31P NMR, and massspectrometry. A broad scope of aliphatic and aromatic acylboronates has been examined, as well as a variety of aryl (pseudo)halides.
我们报告芳基(假)卤化物和硼基酰基阴离子当量之间的催化交叉偶联过程。酰基硼酸酯反应性的这种模式表示极性反转,这通过11 B,31 P NMR和质谱观察到四配位的硼酸酯和酰基钯(II)物种得到支持。已经研究了广泛范围的脂族和芳族酰基硼酸酯,以及各种芳基(假)卤化物。
Direct Access to MIDA Acylboronates through Mild Oxidation of MIDA Vinylboronates
作者:Mathieu L. Lepage、Samson Lai、Nicolas Peressin、Romain Hadjerci、Brian O. Patrick、David M. Perrin
DOI:10.1002/anie.201707125
日期:2017.11.27
Acylboronate esters/trifluoroborates represent an elusive class of boronates that are of increasing interest for both fundamental study as well as applications at the interface of chemistry and biology. Their preparation has been limited by the use of strongly basic anions, often introduced in multistep reactions. Herein, we demonstrate the facile preparation of acylboronate N‐methyliminodiacetyl (MIDA)
Synthesis of Acylborons by Ozonolysis of Alkenylboronates: Preparation of an Enantioenriched Amino Acid Acylboronate
作者:Jumpei Taguchi、Toshiki Ikeda、Rina Takahashi、Ikuo Sasaki、Yasushi Ogasawara、Tohru Dairi、Naoya Kato、Yasunori Yamamoto、Jeffrey W. Bode、Hajime Ito
DOI:10.1002/anie.201707933
日期:2017.10.23
functionalized acylborons are prepared by ozonolysis of alkenyl MIDA boronates. The first synthesis of α-amino acylborons, including the enantiopure alanine-type acylboron was achieved using this method. The products are essential for protein–protein conjugation by potassium acyltrifluroborate ligation. Oligopeptide synthesis using α-amino acylborons proceeded in dilute aqueous medium and the alanine-type acylboron