42224-54-4Relevant academic research and scientific papers
Late-Stage Direct o-Alkenylation of Phenols by PdII-Catalyzed C?H Functionalization
Dou, Yandong,Kenry,Liu, Jiang,Jiang, Jianze,Zhu, Qing
, p. 6896 - 6901 (2019)
o-Alkenylation of unprotected phenols has been developed by direct C?H functionalization catalyzed by PdII. This work features phenol group as a directing group and realizes highly site-selective C?H bond functionalization of phenols to achieve the corresponding products in moderate to excellent yields at 60 °C. The advantages of this reaction include unprecedented C?H functionalization using phenol as a directing group, high regioselectivity, good substrate scope, mild reaction conditions, and high efficiency. To the best of our knowledge, this is the first example of a regioselective C?H alkenylation of unprotected phenols utilizing phenolic hydroxyl group as a directing group. The alkenylation of unprotected tyrosine and intramolecular cyclization are also successfully carried out under this catalytic system in good yields. Furthermore, this novel method enables a late-stage modification of complex phenol-containing bioactive molecules toward a diversity-oriented drug discovery.
Wittig Olefination Using Phosphonium Tetraphenylborate in the Absence of Additional Base
Huang, Wenhua,Zhao, Shuang-Hong,Dong, Guang-Ping
supporting information, p. 1802 - 1810 (2015/10/29)
The thermal decomposition of (substituted methyl)triphenylphosphonium tetraphenylborates, which can also be generated in situ from the corresponding phosphonium halide and NaBPh4, with an aldehyde affords olefins in 22-100% yields. This Wittig olefination does not need use additional base to form phosphorus ylide, and is highly tolerant of benzoic acid.
One-pot Wittig reactions in aqueous media: A rapid and environmentally benign synthesis of α,β-unsaturated carboxylic esters and nitriles
Wu, Jinlong,Yue, Congyong
, p. 2939 - 2947 (2007/10/03)
One-pot Wittig reactions of ethyl bromoacetate and bromoacetonitrile with aldehydes in the presence of PPh3 and LiOH in water were investigated. Most of the olefination reactions completed within 5-120 min in refluxing water containing 1.2 M LiCl to afford the olefin products in 71-97% yields with 100:0-55:45 ratios of E:Z isomers. Copyright Taylor & Francis Group, LLC.
