Solution-phase synthesis and evaluation of tetraproline chiral stationary phases
作者:Zhi Dai、Guozhong Ye、Charles U. Pittman、Tingyu Li
DOI:10.1002/chir.22001
日期:2012.4
solution‐phasesynthesis of multigram amounts of two 9‐fluorenylmethoxycarbonyl (Fmoc)‐protected tetraproline peptides. These tetraproline peptides were then attached to amino derivatized silica gel. The replacement of the Fmoc group with the trimethylacetyl group lead to two tetraprolinechiralstationaryphases (CSPs). A comparison of the chromatographic behavior of these two solution‐phase‐synthesized
Chiral β-amino alcohol-derived N -borane catalysts, namely noncyclic ( 2S )- and ( 2R )-2-amino-2-phenylethanol N -borane and their corresponding cyclic trimeric borazine derivatives, were synthesized and their catalytic activities in the asymmetric reduction of prochiral ketones were examined. Both the noncyclic and cyclic catalysts successfully catalyzed this reaction, giving the desired secondary
preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetrichydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes usecatalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium
手性分子(如醇)对于精细化学品、药物、农用化学品、香料和新型材料的制造至关重要。这些分子需要以高产率和高光学纯度并优先催化生产。在所有的不对称催化反应中,工业上应用最广泛的是与H2(AH)的不对称加氢反应。除了少数例外,这些 AH 工艺使用基于三种关键金属(铑、钌和铱)的催化剂。在本文中,我们描述了一种简单的、工业上可行的铁催化剂,它允许酮的 AH,目前该过程主要由钌和铑催化剂主导。通过将手性 22 元大环配体与廉价、易得的 Fe3(CO)12 结合,多种酮在 50 bar H2 和 45-65 °C 下氢化,提供了非常有价值的手性醇,其对映选择性接近或超过用贵金属催化剂获得的那些。与大多数贵金属催化剂的 AH 相比,铁催化的氢化似乎是非均相的。