Chair of Organic and Medicinal Chemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wyb. Wyspiańskiego 27, 50-370 Wrocław, Poland.
Molecules. 2021 Jun 8;26(12):3493. doi: 10.3390/molecules26123493.
Although many chiral ligands for asymmetric catalysis have been developed, there is still a need for new structures allowing the modular approach. Recently, easy synthesis of chiral pyridine-containing β-amino alcohols has been elaborated by opening respective epoxides with enantiomeric 1-phenylethylamine. This paper reports the synthetic transformation of β-amino alcohols into the new complexing pyridine-containing seleno- and thioethers. The amino alcohols were effectively converted to cyclic sulfonamidates, which were reacted with thiolates or phenyl selenide nucleophile. The reaction was diastereoselective, and its outcome depended on the configuration at the substitution center. The problem was discussed considering DFT optimized structures of both diastereomeric sulfonamidates. New amino-aldimine ligands were also synthesized from chiral pyridine-containing diamines. Nine new chiral ligands were tested in the Tsuji-Trost allylic alkylation resulting in the enantiomerically enriched product in up to 75% ee. The observed stereochemical induction agrees with the prevailing nucleophilic attack at the allylic carbon laying opposite to the complexing nitrogen of pyridine in η-allylic intermediate complexes.
尽管已经开发出许多用于不对称催化的手性配体，但仍需要新的结构来实现模块化方法。最近，通过用对映体 1-苯乙胺开各自的环氧化物，已经详细阐述了手性吡啶基β-氨基醇的简单合成。本文报道了将β-氨基醇转化为新的含螯合吡啶的硒醚和硫醚的合成转化。氨基醇有效地转化为环状磺酰胺酯，然后与硫醇或苯硒化物亲核试剂反应。该反应具有立体选择性，其结果取决于取代中心的构型。考虑到两种非对映异构体磺酰胺酯的 DFT 优化结构，对该问题进行了讨论。还从手性吡啶基二胺合成了新型氨基-醛亚胺配体。在 Tsuji-Trost 烯丙基烷基化反应中测试了 9 种新型手性配体，得到了对映体过量高达 75%ee 的产物。观察到的立体化学诱导与亲核试剂在 η-烯丙基中间配合物中与螯合吡啶的氮相反的烯丙基碳原子上的进攻一致。
