Third-Generation Amino Acid Furanoside-Based Ligands from <scp>d</scp>
-Mannose for the Asymmetric Transfer Hydrogenation of Ketones: Catalysts with an Exceptionally Wide Substrate Scope
作者:Jèssica Margalef、Tove Slagbrand、Fredrik Tinnis、Hans Adolfsson、Montserrat Diéguez、Oscar Pàmies
DOI:10.1002/adsc.201600903
日期:2016.12.22
A modular ligand library of α‐amino acid hydroxyamides and thioamides was prepared from 10 different N‐tert‐butyloxycarbonyl‐protected α‐amino acids and three different amino alcohols derived from 2,3‐O‐isopropylidene‐α‐d‐mannofuranoside. The ligand library was evaluated in the half‐sandwich ruthenium‐ and rhodium‐catalyzed asymmetric transfer hydrogenation of a wide array of ketone substrates, including
由10种不同的N-叔丁氧羰基保护的α-氨基酸和3种衍生自2,3 - O-异亚丙基-α- d的氨基醇制备了α-氨基酸羟酰胺和硫酰胺的模块化配体库甘露呋喃糖苷。在半三明治钌和铑催化的不对称转移氢化反应中,对各种酮类底物进行了评估,包括简单的和空间上要求的芳基烷基酮,芳基氟代烷基酮,杂芳族烷基酮,脂族,共轭和芳族化合物。炔丙基酮。在优化的反应条件下,可以高收率和高达> 99%的对映选择性获得仲醇。配体/催化剂的选择允许生成仲醇的两种对映体,其中钌-羟酰胺和铑-硫代酰胺催化剂彼此互补地起作用。ee。此外,还研究了以伯醇为烷基化和还原剂的苯乙酮和3-乙酰基吡啶的催化串联α-烷基化/不对称转移氢化反应。以最高92%ee的浓度获得了含有延长烷基链的仲醇。