Tandem Friedel‐Crafts‐Alkylation‐Enantioselective‐Protonation by Artificial Enzyme Iminium Catalysis
作者:Reuben B. Leveson‐Gower、Ruben M. Boer、Gerard Roelfes
DOI:10.1002/cctc.202101875
日期:2022.4.22
catalytic residue with an aniline side chain (LmrR_pAF). Building on our previous work showing how LmrR_pAF can catalyse a Friedel-Crafts alkylation of indoles, here we show that when α-substituted acroleins are applied as substrates the protein scaffold enables enantioselectiveprotonation with good selectivity.
a catalytic enamine intermediate represents a challenging, yet fundamentally important process for the synthesis of α‐chiral carbonyls. We describe herein chiral primary‐amine‐catalyzed conjugate additions of indoles to both α‐substituted acroleins and vinyl ketones. These reactions feature enamine protonation as the stereogenic step. A simple primary–tertiary vicinal diamine 1 with trifluoromethanesulfonic
Enamine protonation: A chiral diamine catalyzes an asymmetric Friedel–Crafts reaction through catalytic enantioselectiveprotonation of an enamine. This process can be applied to a range of α‐substituted acroleins and indoles with high yields of products and high enantioselectivity (up to 94 % ee). An OH/π interaction between H2O and the indole ring was found to play an important role in the transition
烯胺质子化:手性二胺通过烯胺的对映选择性质子化催化不对称的Friedel-Crafts反应。该方法可用于一系列α-取代的丙烯醛和吲哚,具有高收率和高对映选择性(最高94%ee)。的O H / H之间的π相互作用2 O和吲哚环,发现发挥在过渡状态中起重要作用(参见方案)。