Purification and Characterization of a (R)-1-Phenyl-1,3-propanediol-producing Enzyme fromTrichosporon fermentansAJ-5152 and Enzymatic (R)-1-Phenyl-1,3-propanediol Production
摘要:
从 Trichosporon fermentans AJ-5152 中纯化出一种 (R)-1-phenyl-1,3-propanediol 产酶。它依赖于 NADPH,能将 3-羟基-1-苯基-1-丙酮(HPPO)转化为(R)-1-苯基-1,3-丙二醇[(R)-PPD],具有抗 Prelog 的特异性。它在 pH 值为 7.0 和温度为 40 °C 时显示出最大活性。它对 HPPO 的 K m 和 V max 值分别为 20.1 mm 和 3.4 μmol min-1 mg protein-1。在凝胶过滤和 SDS 聚丙烯酰胺凝胶电泳中,酶的相对分子量分别估计为 68,000 和 32,000。通过连续加入 HPPO,利用(R)-PPD 生成酶和 NADPH 循环系统进行了(R)-PPD 生成反应。摩尔产率为 76%,生产的(R)-PPD 的光学纯度超过 99%。
liquid leads to a significant improvement of catalyst selectivity. Many organic reactions, including Prins cyclization, cycloaddition of epoxide to aldehyde, and dehydrative etherification of secondary benzyl alcohols, proceed well in formalin or pure water. In particular, tandem dehydration/Prins cyclization reactions of tertiary and secondaryalcohols with formaldehyde were developed for the first time
The Prins reaction of styrenes with paraformaldehyde or 1,3,5-trioxane in toluene in the presence of cation-exchanged montmorillonite (Mn+-mont), which worked as a Brønsted acid catalyst, at 80 °C produced 4-aryl-1,3-dioxanes selectively in up to 99% isolated yield with a turnover number of up to 5.9 × 102. Among the examined 21 Mn+-monts, Ce3+- and Fe3+-monts were revealed to be quite effective. Regeneration of the catalyst was confirmed with the Ce3+-mont, which could be effectively recycled at least three times. Many lanthanide metal ion-exchanged montmorillonites (Ln3+-monts) were prepared and characterized by X-ray powder diffraction (XRD) and temperature-programmed desorption of ammonia gas (NH3-TPD) methods.
The Catalytic Asymmetric Intermolecular Prins Reaction
作者:C. David Díaz-Oviedo、Rajat Maji、Benjamin List
DOI:10.1021/jacs.1c10245
日期:2021.12.15
Despite their significant potential, catalytic asymmetric reactions of olefins with formaldehyde are rare and metal-free approaches have not been previously disclosed. Here we describe an enantioselective intermolecular Prins reaction of styrenes and paraformaldehyde to form 1,3-dioxanes, using confined imino-imidodiphosphate (iIDP) Brønsted acid catalysts. Isotope labeling experiments and computations
尽管它们具有巨大的潜力,但烯烃与甲醛的催化不对称反应是罕见的,并且以前没有公开过不含金属的方法。在这里,我们描述了苯乙烯和多聚甲醛的对映选择性分子间 Prins 反应以形成 1,3-二恶烷,使用受限的亚氨基-亚氨基二磷酸 ( i IDP) 布朗斯台德酸催化剂。同位素标记实验和计算表明酸活化甲醛低聚物向烯烃中的协同、高度异步添加。对映体富集的 1,3-二恶烷可以转化为相应的光学活性 1,3-二醇,它们是有价值的合成构件。
Selective Prins Reaction of Styrenes and Formaldehyde Catalyzed by 2,6-Di-<i>tert</i>-butylphenoxy(difluoro)borane
作者:Thorsten Bach、Johannes Löbel
DOI:10.1055/s-2002-35645
日期:——
The sterically congested Lewis acid 1 was used as a catalyst in the Prins reaction of various styrenes and formaldehyde. 4-Aryl-1,3-dioxanes 5 were selectively formed as the exclusive products of the reaction with styrenes 4a-i and vinylthiophenes 4j-k. The reaction proceeded in most cases with good to excellent yields (55-99%). Styrenes which carried a strongly electron-withdrawing group (CN. CO 2