83-25-0Relevant articles and documents
Metal-free reduction of unsaturated carbonyls, quinones, and pyridinium salts with tetrahydroxydiboron/water
Li, Tiejun,Peng, Henian,Tang, Wenjun,Tian, Duanshuai,Xu, Guangqing,Yang, He
, p. 4327 - 4337 (2021/05/31)
A series of unsaturated carbonyls, quinones, and pyridinium salts have been effectively reduced to the corresponding saturated carbonyls, dihydroxybenzenes, and hydropyridines in moderate to high yields with tetrahydroxydiboron/water as a mild, convenient, and metal-free reduction system. Deuterium-labeling experiments have revealed this protocol to be an exclusive transfer hydrogenation process from water. This journal is
Nucleophilic Substitution at the Guanidine Carbon Center via Guanidine Cyclic Diimide Activation
An, Taeyang,Lee, Yan
supporting information, p. 9163 - 9167 (2021/11/24)
Despite the electron-deficient nature of the guanidine carbon centers, nucleophilic reactions at these sites have been underdeveloped because of the resonance stabilization of the guanidine group. We propose a guanidine C-N bond substitution strategy entailing the formation of guanidine cyclic diimide (GCDI) structures, which effectively destabilize the resonance structure of the guanidine group. In the presence of acid additives, the guanidine carbon center of GCDIs undergoes nucleophilic substitution reactions with various amines and alcohols.
Photoredox/Cobalt-Catalyzed C(sp3)-H Bond Functionalization toward Phenanthrene Skeletons with Hydrogen Evolution
Guo, Jia-Dong,Yang, Xiu-Long,Chen, Bin,Tung, Chen-Ho,Wu, Li-Zhu
supporting information, p. 9627 - 9632 (2020/12/21)
The first example of photoredox strategy for synthesis of phenanthrene skeletons through C(sp3)-H functionalization under external oxidant-free conditions is achieved. This transformation relies on the keto-enol tautomerism of 1,3 dicarbonyl moiety, i.e., the enol form of 1,3-dicarbonyl derivatives with relatively lower oxidation potential can be activated by the excited acridinium photocatalyst. The electron and proton eliminated from the substrate are immediately captured by a cobaloxime catalyst to exclusively afford a-carbonyl radical for highly substituted 10-phenanthrenols in good to excellent yields.
