Dual NHC/photoredox catalytic synthesis of 1,4-diketones using an MR-TADF photocatalyst (DiKTa)
作者:Callum Prentice、James Morrison、Eli Zysman-Colman、Andrew D. Smith
DOI:10.1039/d2cc05705k
日期:——
The use of the recently reported organic multi-resonant thermally activated delayed fluorescence (MR-TADF) photocatalyst DiKTa allows for the modular synthesis of 1,4-diketones under mild and metal-free conditions. The reaction proceeds via a three-component relay process in the presence of an N-heterocyclic carbene (NHC) organocatalyst.
Direct incorporation of two carbonyl groups into a double bond by diacylation is achieved for the first time via visible-light catalysis. Key to success is that N(n-Bu)4+ not only associates with the alkyl anion to avoid protonation, but also activates the α-keto acid to undergo electrophilic addition. The metal-free, redox-neutral and regioselective symmetric and unsymmetric 1,2-dicarbonylation of
通过可见光催化,首次实现了通过二酰化将两个羰基直接结合到双键中。成功的关键是 N( n -Bu) 4 +不仅与烷基阴离子缔合以避免质子化,而且还激活α-酮酸进行亲电加成。烯烃的无金属、氧化还原中性和区域选择性对称和不对称 1,2-二羰基化具有许多应用的潜力。