15905-18-7Relevant articles and documents
Identification of N- or O-Alkylation of Aromatic Nitrogen Heterocycles and N-Oxides Using 1H–15N HMBC NMR Spectroscopy
Bateman, Lorraine M.,Breugst, Martin,Byrne, Peter A.,Flosbach, Niko T.,Sheehy, Kevin J.
, (2020)
A series of representative diazines and pyridine N-oxides were subjected to alkylation using several different alkylating agents. The 15N NMR chemical shifts (δN values) of the diazines, pyridine N-oxides and derived alkylation products were determined using 1H-15N HMBC NMR spectroscopy at natural 15N abundance. The changes in the 15N NMR chemical shifts (Δ(δN) values) that occurred on going from starting materials to products in these reactions were analyzed. N-alkylation of diazines resulted in large upfield shifts of the δN values of the alkylated nitrogen (of the order of 100 ppm or greater). While O-alkylation of pyridine N-oxides resulted in upfield shifts of the δN values of the N-(alkoxy)pyridinium nitrogen, the Δ(δN) values were of a much smaller magnitude (ca. –42 ppm) than those observed for N-alkylations of diazines. Nitrogen NMR spectroscopic data from the literature of relevance to alkylation of azines, diazines, azine N-oxides and diazine N-oxides was gathered together, and using this in tandem with our 15N NMR spectroscopic data, we have been able to corroborate our observations on the trends observed in the Δ(δN) values associated with N- and O-alkylation reactions of aromatic N-heterocycles and N-oxides. An analysis protocol that relies on synergistic evaluation of 1H-15N HMBC and 1H-13C HMBC NMR spectra has been developed that enables unambiguous diagnosis of the occurrence of N-alkylation of aromatic N-heterocycles and O-alkylation of aromatic N-oxides.
Visible-Light-Induced ortho-Selective Migration on Pyridyl Ring: Trifluoromethylative Pyridylation of Unactivated Alkenes
Jeon, Jinwon,He, Yu-Tao,Shin, Sanghoon,Hong, Sungwoo
supporting information, p. 281 - 285 (2019/11/26)
The photocatalyzed ortho-selective migration on a pyridyl ring has been achieved for the site-selective trifluoromethylative pyridylation of unactivated alkenes. The overall process is initiated by the selective addition of a CF3 radical to the alkene to provide a nucleophilic alkyl radical intermediate, which enables an intramolecular endo addition exclusively to the ortho-position of the pyridinium salt. Both secondary and tertiary alkyl radicals are well-suited for addition to the C2-position of pyridinium salts to ultimately provide synthetically valuable C2-fluoroalkyl functionalized pyridines. Moreover, the method was successfully applied to the reaction with P-centered radicals. The utility of this transformation was further demonstrated by the late-stage functionalization of complex bioactive molecules.
INHIBITORS OF COLLAGEN PROLYL 4-HYDROXYLASE
-
Paragraph 0187; 0188; 0189, (2016/10/17)
Biheteroaryl dicarboxylates and esters, and salts thereof which are useful as modulators of CP4H activity and more particularly as inhibitors of CP4H. Compounds of formula: and salts thereof where: X is S, O, NH, or NR, where R is an alkyl group having 1-3 carbon atoms; R1 and R2 independently are —OR7, or —NHSO2R8, where R7 is selected from: hydrogen, alkyl, alkenyl, alkoxyalkyl, —R′—CO—R″, —R′—CO—O—R″, —CO—R″, —R′—O—CO—R″, —R′—CO—NR″, —CO—NR″, or —R′—O—CO—NR″, and R8 is selected from hydrogen, alkyl, aryl, arylalkyl; R3, R4 and R6 independently are hydrogen, alkyl, alkoxy, alkenyl, alkenoxy, halo alkyl, haloalkenyl, halogen, hydroxyl, hydroxyalkyl, hydroxyalkenyl, aryl, aryloxy, arylalkyl or arylalkyloxy; R5 is hydrogen, halogen, alkyl having 1-3 carbon atoms, or alkoxy having 1-3 carbon atoms; —R′— is a divalent straight chain or branched alkylene, and —R″ is an alkyl, alkenyl, arylalkyl, or aryl group. Methods for inhibition of CP4H in vivo and in vitro.
