ChemInform Abstract: Nickel-Catalyzed Reductive Cleavage of Aryl Alkyl Ethers to Arenes in Absence of External Reductant.

ChemInform ◽  
2015 ◽  
Vol 46 (37) ◽  
pp. no-no
Author(s):  
Mamoru Tobisu ◽  
Toshifumi Morioka ◽  
Akimichi Ohtsuki ◽  
Naoto Chatani
2015 ◽  
Vol 6 (6) ◽  
pp. 3410-3414 ◽  
Author(s):  
Mamoru Tobisu ◽  
Toshifumi Morioka ◽  
Akimichi Ohtsuki ◽  
Naoto Chatani

A nickel catalyst for reductive cleavage of aryl ethers in the absence of an external reductant is developed. The alkoxy group of the substrate serves as an internal reductant.


2019 ◽  
Author(s):  
Patrick Fier ◽  
Suhong Kim ◽  
Kevin M. Maloney

Sulfonamides are pervasive in drugs and agrochemicals, yet are typically considered as terminal functional groups rather than synthetic handles. To enable the general late-stage functionalization of secondary sulfonamides, we have developed a mild and general method to reductively cleave the N-S bonds of sulfonamides to generate sulfinates and amines, components which can further react <i>in-situ</i> to access a variety of other medicinally relevant functional groups. The utility of this platform is highlighted by the selective manipulation of several complex bioactive molecules.


2020 ◽  
Vol 24 (19) ◽  
pp. 2272-2282
Author(s):  
Vu Ngoc Toan ◽  
Nguyen Minh Tri ◽  
Nguyen Dinh Thanh

Several 6- and 7-alkoxy-2-oxo-2H-chromene-4-carbaldehydes were prepared from corresponding alkyl ethers of 6- and 7-hydroxy-4-methyl-2-oxo-2H-chromen-2-ones by oxidation using selenium dioxide. 6- and 7-Alkoxy-4-methyl-2H-chromenes were obtained with yields of 57-85%. Corresponding 4-carbaldehyde derivatives were prepared with yields of 41-67%. Thiosemicarbazones of these aldehydes with D-galactose moiety were synthesized by reaction of these aldehydes with N-(2,3,4,6-tetra-O-acetyl-β-Dgalactopyranosyl) thiosemicarbazide with yields of 62-74%. These thiosemicarbazones were screened for their antibacterial and antifungal activities in vitro against bacteria, such as Staphylococcus aureus, Escherichia coli, and fungi, such as Aspergillus niger, Candida albicans. Several compounds exhibited strong inhibitory activity with MIC values of 0.78- 1.56 μM, including 8a (against S. aureus, E. coli, and C. albicans), 8d (against E. coli and A. niger), 9a (against S. aureus), and 9c (against S. aureus and C. albicans).


1980 ◽  
Vol 45 (7) ◽  
pp. 1959-1963 ◽  
Author(s):  
Dušan Joniak ◽  
Božena Košíková ◽  
Ludmila Kosáková

Methyl 4-O-(3-methoxy-4-hydroxybenzyl) and methyl 4-O-(3,5-dimethoxy-4-hydroxybenzyl)-α-D-glucopyranoside and their 6-O-isomers were prepared as model substances for the ether lignin-saccharide bond by reductive cleavage of corresponding 4,6-O-benzylidene derivatives. Kinetic study of acid-catalyzed hydrolysis of the compounds prepared was carried out by spectrophotometric determination of the benzyl alcoholic groups set free, after their reaction with quinonemonochloroimide, and it showed the low stability of the p-hydroxybenzyl ether bond.


Science ◽  
2021 ◽  
Vol 372 (6538) ◽  
pp. 175-182
Author(s):  
Hairong Lyu ◽  
Ilia Kevlishvili ◽  
Xuan Yu ◽  
Peng Liu ◽  
Guangbin Dong

Mild methods to cleave the carbon-oxygen (C−O) bond in alkyl ethers could simplify chemical syntheses through the elaboration of these robust, readily available precursors. Here we report that dibromoboranes react with alkyl ethers in the presence of a nickel catalyst and zinc reductant to insert boron into the C−O bond. Subsequent reactivity can effect oxygen-to-nitrogen substitution or one-carbon homologation of cyclic ethers and more broadly streamline preparation of bioactive compounds. Mechanistic studies reveal a cleavage-then-rebound pathway via zinc/nickel tandem catalysis.


1982 ◽  
Vol 47 (22) ◽  
pp. 4250-4254 ◽  
Author(s):  
Kundanbhai M. Patel ◽  
Richard J. Baltisberger ◽  
Virgil I. Stenberg ◽  
Neil F. Woolsey

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