35740-86-4Relevant articles and documents
Catalytic Enantioselective Synthesis of Heterocyclic Vicinal Fluoroamines by Using Asymmetric Protonation: Method Development and Mechanistic Study
Ashford, Matthew W.,Xu, Chao,Molloy, John J.,Carpenter-Warren, Cameron,Slawin, Alexandra M. Z.,Leach, Andrew G.,Watson, Allan J. B.
supporting information, p. 12249 - 12255 (2020/08/21)
A catalytic enantioselective synthesis of heterocyclic vicinal fluoroamines is reported. A chiral Br?nsted acid promotes aza-Michael addition to fluoroalkenyl heterocycles to give a prochiral enamine intermediate that undergoes asymmetric protonation upon rearomatization. The reaction accommodates a range of azaheterocycles and nucleophiles, generating the C?F stereocentre in high enantioselectivity, and is also amenable to stereogenic C?CF3 bonds. Extensive DFT calculations provided evidence for stereocontrolled proton transfer from catalyst to substrate as the rate-determining step, and showed the importance of steric interactions from the catalyst's alkyl groups in enforcing the high enantioselectivity. Crystal structure data show the dominance of noncovalent interactions in the core structure conformation, enabling modulation of the conformational landscape. Ramachandran-type analysis of conformer distribution and Protein Data Bank mining indicated that benzylic fluorination by this approach has the potential to improve the potency of several marketed drugs.
A highly practical and convenient halogenation of fused heterocyclic N-oxides
Wang, Dong,Wang, Yuxi,Zhao, Junjie,Li, Linna,Miao, Longfei,Wang, Dong,Sun, Hua,Yu, Peng
, p. 5762 - 5768 (2016/08/30)
A novel, simple and practical method for the regioselective halogenation of fused heterocyclic N-oxides has been developed. It employs Vilsmeier reagent, generated in situ by POX3and DMF, as both the activating agent and the nucleophilic halide source. The method is amenable across a broad range of substrates, including quinolines, isoquinolines and the diazine N-oxides, possessing a variety of substitution patterns. Furthermore, all of the reagents associated are cheap and easy to obtain. The potential extension of this method to a one-pot oxidation/halogenation sequence that obviates the need for isolation of the N-oxide intermediates is also presented.
Development of a facile and inexpensive route for the preparation of α-halobenzopyridines from α-unsubstituted benzopyridines
Sugimoto, Osamu,Iwasaki, Hyuma,Tanji, Ken-Ichi
, p. 1445 - 1454 (2015/07/15)
A facile and inexpensive route for the preparation of α-halobenzopyridines from α-unsubstituted benzopyridines via N-methylbenzopyridin-α-ones was developed. α-Unsubstituted benzopyridines were converted easily into the corresponding N-methylbenzopyridin-α-ones, which were halogenated using PPh3-TCICA or PPh3-DBICA without using solvent to give α-halobenzopyridines.
