Divergent Access to (1,1) and (1,2)‐Azidolactones from Alkenes using Hypervalent Iodine Reagents
作者:Sébastien Alazet、Franck Le Vaillant、Stefano Nicolai、Thibaut Courant、Jerome Waser
DOI:10.1002/chem.201702599
日期:2017.7.18
versatile synthesis of azidolactones through azidation and cyclization of carboxylic acids onto alkenes has been developed. Based on either photoredox or palladium catalysis, (1,1) and (1,2) azido lactones can be selectively synthesized. The choice of catalyst and benziodoxol(on)e reagent serving as azide source was essential to initiate either a radical or Lewis acid mediated process with divergent
Cobalt-catalyzed oxidative cyclization of gem -disubstituted conjugated alkenols
作者:Tânia M.F. Alves、Mateus O. Costa、Beatriz A.D. Bispo、Fabiana L. Pedrosa、Marco A.B. Ferreira
DOI:10.1016/j.tetlet.2016.06.064
日期:2016.7
Aryl gem-disubstituted conjugated alkenols underwent oxidativecyclization affording 2,5,5-trisubstituted tetrahydrofurans in reasonable yields and good diastereoselectivities using the reductive termination variation of the Mukaiyama aerobic oxidative reaction. Under oxidative termination, the same alkenols produced diols and ketonic by-products via the double hydration and beta-scission competing
Cooperativity within the catalyst: alkoxyamide as a catalyst for bromocyclization and bromination of (hetero)aromatics
作者:Haripriyo Mondal、Md Raja Sk、Modhu Sudan Maji
DOI:10.1039/d0cc04673f
日期:——
Alkoxyamide has been reported as a catalyst for the activation of N-bromosuccinimide to perform bromocyclization and bromination of a wide range of substrates in a lipophilic solvent, where adequate suppression of the background reactions was observed. The key feature of the active site is the alkoxy group attached to the sulfonamide moiety, which facilitates the acceptance as well as the delivery
Numerous electrophilic thiocyano oxyfunctionalization reactions of alkenes have been achieved using N-thiocyano-dibenzenesulfonimide, which is a newelectrophilic thiocyanation reagent and could be easily prepared in two steps from dibenzenesulfonimide. This approach provides efficient, simple, and modular methods for the formation of SCN-containing heterocycles such as lactones, tetrahydrofurans,
Synthesis of Chiral Sulfonyl Lactones via Copper-Catalyzed Asymmetric Radical Reaction of DABCO⋅(SO<sub>2</sub>
)
作者:Yang Wang、Lingling Deng、Jie Zhou、Xiaochen Wang、Haibo Mei、Jianlin Han、Yi Pan
DOI:10.1002/adsc.201701532
日期:2018.3.20
work, an asymmetriccopper‐catalyzed radical multi‐component cascade reaction of an unsaturated carboxylic acid, aryldiazonium tetrafluoroborate, and DABCO⋅(SO2)2 (DABSO) has been developed for the enantioselective synthesis of sulfonyl lactones. In this reaction, this SO2 surrogate, DABSO was applied for the first time in the construction of chiral compounds. This multiple‐step asymmetric radical reaction