932-66-1Relevant articles and documents
“Release and Catch” Effect of Perfluoroalkylsulfonylimide-Functionalized Imidazole/Pyridine on Br?nsted Acids in Organic Systems
You, Li,Ren, Xiao-Fei,Wang, Yun,Ma, Zhong-Hua,Gu, Yanlong,Ma, Jing-Zhong
, p. 3394 - 3401 (2016)
A “release and catch” method was developed by utilising the scavenging effect of a fluorous zwitterion on a homogeneous triflic acid (TfOH) catalyst in Michael addition and Rupe rearrangement. Both TfOH and the zwitterion were recycled with >90 % recovery using toluene. The zwitterions were designed by functionalising imidazole/pyridine with the perfluoroalkylsulfonylimide group. The “caught” TfOH was delivered to ethyl acetate and re-used. The smooth delivery was primarily because of the fluorous tail of the zwitterion, the hydrophobicity of which probably weakened the ability of the zwitterion to form H bonds, so that retro-ion-exchange occurred towards the formation of the acid and zwitterion. The method was universal for other strong Br?nsted acids such as H2SO4 and p-MeC6H4SO3H. The method combined the significant advantages of homogeneous catalysis and heterogeneous isolation. Based on the H0 acidity function and the 31P NMR chemical shift of Et3P=O adducts, it is reasonable to deduce that the decrease of the acid strength of the formed composites of Br?nsted acids and the zwitterion drove the scavenging effect.
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Nasarow et al.
, (1956)
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Hydration of terminal alkynes catalyzed by cobalt corrole complex
Lai, Jia-Wei,Liu, Zhao-Yang,Chen, Xiao-Yan,Zhang, Hao,Liu, Hai-Yang
supporting information, (2020/10/02)
Cobalt(III) corrole was firstly applied to the hydration of terminal alkynes. The alkyne hydration proceeded in good to excellent yield with 0.03 to 0.3 mol% cobalt corrole catalyst loading. A wide range of substrates were tolerated. Particularly, the reaction can give 90% yield in a gram scale experiment.
Phosphorous acid promoted isomerization of propargyl alcohols to α,β-unsaturated carbonyl compounds
Gan, Xiaotang,Fu, Zuqi,Liu,Yan, Yani,Chen, Chao,Zhou, Yongbo,Dong, Jianyu
, (2019/07/12)
A metal-free and two-phase protocol for the Meyer-Schuster isomerization of propargyl alcohols to the corresponding α,β-unsaturated carbonyl compounds has been achieved in the presence of stoichiometric phosphorous acid aqueous solution, which produces the desired products in high yields with excellent stereoselectivity. Compared with the traditional methods, the procedure features broad scope of the substrates, mild conditions, and easy separation, providing an appealing alternative to the Meyer-Schuster reaction.
