673-22-3Relevant articles and documents
Formylation of activated arenes by phenyl formate: Implications for the mechanism of the Fries rearrangement of aryl formates
Bagno, Alessandro,Kantiehner, Willi,Saielli, Giacomo
, p. 682 - 687 (2008)
We present an NMR and DFT investigation of the reaction of phenyl formate with 3-methoxyphenol and 3,5-dimethoxyphenol with excess BCl3. The products obtained (3-methoxy- and 3,5-dimethoxy-salicylaldehyde, respectively) are the same as those resulting from the Fries rearrangement of 3-methoxy- and 3,5-dimethoxy-phenyl formate. These results represent a novel regioselective synthetic route to aromatic aldehydes, using phenyl formate as a source of formylating agent. They also unambiguously prove that the Fries rearrangement of aryl formates (that we recently investigated in J. Org. Chem. 71, 9331-9340, 2006) is intermolecular: the intermediate formyl chloride is released in situ and, in turn, it formylates the intermediate dichloroborate ester of 3-methoxy- and 3,5-dimethoxy-phenol in a second independent step. The -BCl2 moiety bound to the aryl oxygen of the substituted phenol interacts with the formyl chloride strongly favouring the ortho substitution. Copyright
Anchimerically Assisted Selective Cleavage of Acid-Labile Aryl Alkyl Ethers by Aluminum Triiodide and N, N-Dimethylformamide Dimethyl Acetal
Sang, Dayong,Yue, Huaxin,Zhao, Zhengdong,Yang, Pengtao,Tian, Juan
, p. 6429 - 6440 (2020/07/14)
Aluminum triiodide is harnessed by N,N-dimethylformamide dimethyl acetal (DMF-DMA) for the selective cleavage of ethers via neighboring group participation. Various acid-labile functional groups, including carboxylate, allyl, tert-butyldimethylsilyl (TBS), and tert-butoxycarbonyl (Boc), suffer the conditions intact. The method offers an efficient approach to cleaving catechol monoalkyl ethers and to uncovering phenols from acetal-type protecting groups such as methoxymethyl (MOM), methoxyethoxymethyl (MEM), and tetrahydropyranyl (THP) chemoselectively.
Catalytic oxidation of alcohols and alkyl benzenes to carbonyls using Fe3O4?SiO2?(TEMPO)-: Co -(Chlorophyll-CoIII) as a bi-functional, self-co-oxidant nanocatalyst
Hamah-Ameen, Baram Ahmed,Kazemnejadi, Milad,Mahmoudi, Boshra,Rostami, Amin
, p. 6600 - 6613 (2020/11/16)
Chlorophyll b was extracted from heliotropium europaeum plant, demetalated, allylated and grafted to acrylated TEMPO through a copolymerization protocol. Then, the chlorophyll monomers were coordinated to Co ions, immobilized on magnetic nanoparticles and the resulting hybrid was used as a powerful catalyst for a variety of oxidation reactions. By using the present method, oxidation of benzylic alcohols and alkyl benzenes to carbonyls was accomplished in water under aerobic conditions. Moreover, direct oxidation of alcohols to carboxylic acids was performed by adding NaOCl to the mixture. All entries were oxidized to the corresponding desired product with high to excellent yields and up to 97% selectivity. The catalyst was thoroughly characterized by CV, TGA, VSM, XRD, XPS, DLS, FE-SEM, TEM, UV-Vis, EDX, and BET analyses. The activity of the catalyst was investigated by applying various components of the catalyst to the oxidation model separately. The reasonable mechanisms are suggested based on the cooperation between the TEMPO groups and cobalt(iii) (or Co(iv)) sites on the catalyst. The catalyst could be recovered and reused for at least 7 consecutive recycles without any considerable reactivity loss. This journal is
