4619-18-5Relevant articles and documents
A heavy-metal-free desulfonylative Giese-type reaction of benzothiazole sulfones under visible-light conditions
Inuzuka, Toshiyasu,Iwama, Haruka,Ogawa, Daichi,Sengoku, Tetsuya,Yoda, Hidemi
, p. 9858 - 9861 (2021/10/12)
A visible-light-induced desulfonylative Giese-type reaction has been developed. Essential to the success is the employment of Hantzsch ester to activate benzothiazole sulfones without any heavy-metal additives. Not only benzylic benzothiazole sulfones but also alkyl ones were viable substrates and reacted with electron-deficient alkenes and a propiol amide.
Ligand-Controlled Regiodivergence in Nickel-Catalyzed Hydroarylation and Hydroalkenylation of Alkenyl Carboxylic Acids**
Deng, Ruohan,Engle, Keary M.,Fu, Yue,Gao, Yang,Li, Zi-Qi,Liu, Peng,Tran, Van T.
supporting information, p. 23306 - 23312 (2020/10/19)
A nickel-catalyzed regiodivergent hydroarylation and hydroalkenylation of unactivated alkenyl carboxylic acids is reported, whereby the ligand environment around the metal center dictates the regiochemical outcome. Markovnikov hydrofunctionalization products are obtained under mild ligand-free conditions, with up to 99 % yield and >20:1 selectivity. Alternatively, anti-Markovnikov products can be accessed with a novel 4,4-disubstituted Pyrox ligand in excellent yield and >20:1 selectivity. Both electronic and steric effects on the ligand contribute to the high yield and selectivity. Mechanistic studies suggest a change in the turnover-limiting and selectivity-determining step induced by the optimal ligand. DFT calculations reveal that in the anti-Markovnikov pathway, repulsion between the ligand and the alkyl group is minimized (by virtue of it being 1° versus 2°) in the rate- and regioselectivity-determining transmetalation transition state.
Synthesis of Novel Pterocarpen Analogues via [3?+?2] Coupling-Elimination Cascade of α,α-Dicyanoolefins with Quinone Monoimines
Chen, Hui,Zhao, Sihan,Cheng, Shaobing,Dai, Xingjie,Xu, Xiaoying,Yuan, Weicheng,Zhang, Xiaomei
, p. 1672 - 1683 (2019/04/08)
By employing triethylamine as a catalyst, [3?+?2] coupling-elimination cascade of α,α-dicyanoolefins with quinone monoimines was realized. The reactions afforded various novel pterocarpen analogues with generally moderate yields (up to 75%). In addition, a plausible reaction mechanism was proposed.