62456-75-1Relevant articles and documents
Ring Expansion Fluorination of Unactivated Cyclopropanes Mediated by a New Monofluoroiodane(III) Reagent
Chen, Ze,Du, Feng-Huan,Hu, Ze-Nan,Jia, Meng-Cheng,Ren, Jing,Zhang, Chi
supporting information, p. 24171 - 24178 (2021/10/08)
Herein, we report a new strategy for carbon?carbon bond scission and intramolecular ring expansion fluorination of unactivated cyclopropanes, which was accomplished with a new hypervalent fluoroiodane(III) reagent 1. This novel method delivers medicinally relevant 4-fully substituted fluoropiperidines in moderate to high yields with excellent regio- and diastereoselectivity. Reagent 1, which has an N-acetylbenziodazole framework, was readily synthesized via three steps in 76 % overall yield and was characterized by NMR spectroscopy and X-ray crystallography. Owing to the presence of a secondary I???O bonding interaction between the λ3-iodane atom and the carbonyl oxygen of the acetyl group of the N-acetylbenziodazole framework, 1 has excellent stability and can be stored at ambient temperature for 6 months without any detectable decomposition. Density functional theory calculations and experimental studies showed that the reaction proceeds via a carbocation intermediate that readily combines with a fluoride ion to generate the product.
Asymmetric Synthesis of β2-Aryl Amino Acids through Pd-Catalyzed Enantiospecific and Regioselective Ring-Opening Suzuki–Miyaura Arylation of Aziridine-2-carboxylates
Takeda, Youhei,Matsuno, Tetsuya,Sharma, Akhilesh K.,Sameera,Minakata, Satoshi
supporting information, p. 10226 - 10231 (2019/07/18)
A Pd-catalyzed enantiospecific and regioselective ring-opening Suzuki–Miyaura arylation of aziridine-2-carboxylates was developed. The cross-coupling allows for the asymmetric preparation of enantioenriched β2-aryl amino acids, starting from co
Mechanistic Insight into Palladium-Catalyzed Cycloisomerization: A Combined Experimental and Theoretical Study
Mekareeya, Aroonroj,Walker, P. Ross,Couce-Rios, Almudena,Campbell, Craig D.,Steven, Alan,Paton, Robert S.,Anderson, Edward A.
supporting information, p. 10104 - 10114 (2017/08/03)
The cycloisomerization of enynes catalyzed by Pd(OAc)2 and bis-benzylidene ethylenediamine (bbeda) is a landmark methodology in transition-metal-catalyzed cycloisomerization. However, the mechanistic pathway by which this reaction proceeds has remained unclear for several decades. Here we describe mechanistic investigations into this reaction using enynamides, which deliver azacycles with high regio- and stereocontrol. Extensive 1H NMR spectroscopic studies and isotope effects support a palladium(II) hydride-mediated pathway and reveal crucial roles of bbeda, water, and the precise nature of the Pd(OAc)2 pre-catalyst. Computational studies support these mechanistic findings and lead to a clear picture of the origins of the high stereocontrol that can be achieved in this transformation, as well as suggesting a novel mechanism by which hydrometalation proceeds.
